Commit Graph

44800 Commits

Author SHA1 Message Date
Linus Torvalds
3a56e24173 for-6.11/io_uring-20240714
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Merge tag 'for-6.11/io_uring-20240714' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:
 "Here are the io_uring updates queued up for 6.11.

  Nothing major this time around, various minor improvements and
  cleanups/fixes. This contains:

   - Add bind/listen opcodes. Main motivation is to support direct
     descriptors, to avoid needing a regular fd just for doing these two
     operations (Gabriel)

   - Probe fixes (Gabriel)

   - Treat io-wq work flags as atomics. Not fixing a real issue, but may
     as well and it silences a KCSAN warning (me)

   - Cleanup of rsrc __set_current_state() usage (me)

   - Add 64-bit for {m,f}advise operations (me)

   - Improve performance of data ring messages (me)

   - Fix for ring message overflow posting (Pavel)

   - Fix for freezer interaction with TWA_NOTIFY_SIGNAL. Not strictly an
     io_uring thing, but since TWA_NOTIFY_SIGNAL was originally added
     for faster task_work signaling for io_uring, bundling it with this
     pull (Pavel)

   - Add Pavel as a co-maintainer

   - Various cleanups (me, Thorsten)"

* tag 'for-6.11/io_uring-20240714' of git://git.kernel.dk/linux: (28 commits)
  io_uring/net: check socket is valid in io_bind()/io_listen()
  kernel: rerun task_work while freezing in get_signal()
  io_uring/io-wq: limit retrying worker initialisation
  io_uring/napi: Remove unnecessary s64 cast
  io_uring/net: cleanup io_recv_finish() bundle handling
  io_uring/msg_ring: fix overflow posting
  MAINTAINERS: change Pavel Begunkov from io_uring reviewer to maintainer
  io_uring/msg_ring: use kmem_cache_free() to free request
  io_uring/msg_ring: check for dead submitter task
  io_uring/msg_ring: add an alloc cache for io_kiocb entries
  io_uring/msg_ring: improve handling of target CQE posting
  io_uring: add io_add_aux_cqe() helper
  io_uring: add remote task_work execution helper
  io_uring/msg_ring: tighten requirement for remote posting
  io_uring: Allocate only necessary memory in io_probe
  io_uring: Fix probe of disabled operations
  io_uring: Introduce IORING_OP_LISTEN
  io_uring: Introduce IORING_OP_BIND
  net: Split a __sys_listen helper for io_uring
  net: Split a __sys_bind helper for io_uring
  ...
2024-07-15 13:49:10 -07:00
Linus Torvalds
b051320d6a vfs-6.11.misc
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Merge tag 'vfs-6.11.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:

   - Support passing NULL along AT_EMPTY_PATH for statx().

     NULL paths with any flag value other than AT_EMPTY_PATH go the
     usual route and end up with -EFAULT to retain compatibility (Rust
     is abusing calls of the sort to detect availability of statx)

     This avoids path lookup code, lockref management, memory allocation
     and in case of NULL path userspace memory access (which can be
     quite expensive with SMAP on x86_64)

   - Don't block i_writecount during exec. Remove the
     deny_write_access() mechanism for executables

   - Relax open_by_handle_at() permissions in specific cases where we
     can prove that the caller had sufficient privileges to open a file

   - Switch timespec64 fields in struct inode to discrete integers
     freeing up 4 bytes

  Fixes:

   - Fix false positive circular locking warning in hfsplus

   - Initialize hfs_inode_info after hfs_alloc_inode() in hfs

   - Avoid accidental overflows in vfs_fallocate()

   - Don't interrupt fallocate with EINTR in tmpfs to avoid constantly
     restarting shmem_fallocate()

   - Add missing quote in comment in fs/readdir

  Cleanups:

   - Don't assign and test in an if statement in mqueue. Move the
     assignment out of the if statement

   - Reflow the logic in may_create_in_sticky()

   - Remove the usage of the deprecated ida_simple_xx() API from procfs

   - Reject FSCONFIG_CMD_CREATE_EXCL requets that depend on the new
     mount api early

   - Rename variables in copy_tree() to make it easier to understand

   - Replace WARN(down_read_trylock, ...) abuse with proper asserts in
     various places in the VFS

   - Get rid of user_path_at_empty() and drop the empty argument from
     getname_flags()

   - Check for error while copying and no path in one branch in
     getname_flags()

   - Avoid redundant smp_mb() for THP handling in do_dentry_open()

   - Rename parent_ino to d_parent_ino and make it use RCU

   - Remove unused header include in fs/readdir

   - Export in_group_capable() helper and switch f2fs and fuse over to
     it instead of open-coding the logic in both places"

* tag 'vfs-6.11.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits)
  ipc: mqueue: remove assignment from IS_ERR argument
  vfs: rename parent_ino to d_parent_ino and make it use RCU
  vfs: support statx(..., NULL, AT_EMPTY_PATH, ...)
  stat: use vfs_empty_path() helper
  fs: new helper vfs_empty_path()
  fs: reflow may_create_in_sticky()
  vfs: remove redundant smp_mb for thp handling in do_dentry_open
  fuse: Use in_group_or_capable() helper
  f2fs: Use in_group_or_capable() helper
  fs: Export in_group_or_capable()
  vfs: reorder checks in may_create_in_sticky
  hfs: fix to initialize fields of hfs_inode_info after hfs_alloc_inode()
  proc: Remove usage of the deprecated ida_simple_xx() API
  hfsplus: fix to avoid false alarm of circular locking
  Improve readability of copy_tree
  vfs: shave a branch in getname_flags
  vfs: retire user_path_at_empty and drop empty arg from getname_flags
  vfs: stop using user_path_at_empty in do_readlinkat
  tmpfs: don't interrupt fallocate with EINTR
  fs: don't block i_writecount during exec
  ...
2024-07-15 10:52:51 -07:00
Linus Torvalds
365346980e - Fix a performance regression when measuring the CPU time of a thread
(clock_gettime(CLOCK_THREAD_CPUTIME_ID,...)) due to the addition of
   PSI IRQ time accounting in the hotpath
 
 - Fix a task_struct leak due to missing to decrement the refcount when
   the task is enqueued before the timer which is supposed to do that,
   expires
 
 - Revert an attempt to expedite detaching of movable tasks, as finding
   those could become very costly. Turns out the original issue wasn't
   even hit by anyone
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Merge tag 'sched_urgent_for_v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Borislav Petkov:

 - Fix a performance regression when measuring the CPU time of a thread
   (clock_gettime(CLOCK_THREAD_CPUTIME_ID,...)) due to the addition of
   PSI IRQ time accounting in the hotpath

 - Fix a task_struct leak due to missing to decrement the refcount when
   the task is enqueued before the timer which is supposed to do that,
   expires

 - Revert an attempt to expedite detaching of movable tasks, as finding
   those could become very costly. Turns out the original issue wasn't
   even hit by anyone

* tag 'sched_urgent_for_v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Move psi_account_irqtime() out of update_rq_clock_task() hotpath
  sched/deadline: Fix task_struct reference leak
  Revert "sched/fair: Make sure to try to detach at least one movable task"
2024-07-14 10:18:25 -07:00
Pavel Begunkov
943ad0b62e kernel: rerun task_work while freezing in get_signal()
io_uring can asynchronously add a task_work while the task is getting
freezed. TIF_NOTIFY_SIGNAL will prevent the task from sleeping in
do_freezer_trap(), and since the get_signal()'s relock loop doesn't
retry task_work, the task will spin there not being able to sleep
until the freezing is cancelled / the task is killed / etc.

Run task_works in the freezer path. Keep the patch small and simple
so it can be easily back ported, but we might need to do some cleaning
after and look if there are other places with similar problems.

Cc: stable@vger.kernel.org
Link: https://github.com/systemd/systemd/issues/33626
Fixes: 12db8b6900 ("entry: Add support for TIF_NOTIFY_SIGNAL")
Reported-by: Julian Orth <ju.orth@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/89ed3a52933370deaaf61a0a620a6ac91f1e754d.1720634146.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-07-11 01:51:44 -06:00
Kumar Kartikeya Dwivedi
a6fcd19d7e bpf: Defer work in bpf_timer_cancel_and_free
Currently, the same case as previous patch (two timer callbacks trying
to cancel each other) can be invoked through bpf_map_update_elem as
well, or more precisely, freeing map elements containing timers. Since
this relies on hrtimer_cancel as well, it is prone to the same deadlock
situation as the previous patch.

It would be sufficient to use hrtimer_try_to_cancel to fix this problem,
as the timer cannot be enqueued after async_cancel_and_free. Once
async_cancel_and_free has been done, the timer must be reinitialized
before it can be armed again. The callback running in parallel trying to
arm the timer will fail, and freeing bpf_hrtimer without waiting is
sufficient (given kfree_rcu), and bpf_timer_cb will return
HRTIMER_NORESTART, preventing the timer from being rearmed again.

However, there exists a UAF scenario where the callback arms the timer
before entering this function, such that if cancellation fails (due to
timer callback invoking this routine, or the target timer callback
running concurrently). In such a case, if the timer expiration is
significantly far in the future, the RCU grace period expiration
happening before it will free the bpf_hrtimer state and along with it
the struct hrtimer, that is enqueued.

Hence, it is clear cancellation needs to occur after
async_cancel_and_free, and yet it cannot be done inline due to deadlock
issues. We thus modify bpf_timer_cancel_and_free to defer work to the
global workqueue, adding a work_struct alongside rcu_head (both used at
_different_ points of time, so can share space).

Update existing code comments to reflect the new state of affairs.

Fixes: b00628b1c7 ("bpf: Introduce bpf timers.")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240709185440.1104957-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-10 15:59:44 -07:00
Kumar Kartikeya Dwivedi
d4523831f0 bpf: Fail bpf_timer_cancel when callback is being cancelled
Given a schedule:

timer1 cb			timer2 cb

bpf_timer_cancel(timer2);	bpf_timer_cancel(timer1);

Both bpf_timer_cancel calls would wait for the other callback to finish
executing, introducing a lockup.

Add an atomic_t count named 'cancelling' in bpf_hrtimer. This keeps
track of all in-flight cancellation requests for a given BPF timer.
Whenever cancelling a BPF timer, we must check if we have outstanding
cancellation requests, and if so, we must fail the operation with an
error (-EDEADLK) since cancellation is synchronous and waits for the
callback to finish executing. This implies that we can enter a deadlock
situation involving two or more timer callbacks executing in parallel
and attempting to cancel one another.

Note that we avoid incrementing the cancelling counter for the target
timer (the one being cancelled) if bpf_timer_cancel is not invoked from
a callback, to avoid spurious errors. The whole point of detecting
cur->cancelling and returning -EDEADLK is to not enter a busy wait loop
(which may or may not lead to a lockup). This does not apply in case the
caller is in a non-callback context, the other side can continue to
cancel as it sees fit without running into errors.

Background on prior attempts:

Earlier versions of this patch used a bool 'cancelling' bit and used the
following pattern under timer->lock to publish cancellation status.

lock(t->lock);
t->cancelling = true;
mb();
if (cur->cancelling)
	return -EDEADLK;
unlock(t->lock);
hrtimer_cancel(t->timer);
t->cancelling = false;

The store outside the critical section could overwrite a parallel
requests t->cancelling assignment to true, to ensure the parallely
executing callback observes its cancellation status.

It would be necessary to clear this cancelling bit once hrtimer_cancel
is done, but lack of serialization introduced races. Another option was
explored where bpf_timer_start would clear the bit when (re)starting the
timer under timer->lock. This would ensure serialized access to the
cancelling bit, but may allow it to be cleared before in-flight
hrtimer_cancel has finished executing, such that lockups can occur
again.

Thus, we choose an atomic counter to keep track of all outstanding
cancellation requests and use it to prevent lockups in case callbacks
attempt to cancel each other while executing in parallel.

Reported-by: Dohyun Kim <dohyunkim@google.com>
Reported-by: Neel Natu <neelnatu@google.com>
Fixes: b00628b1c7 ("bpf: Introduce bpf timers.")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240709185440.1104957-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-10 15:59:44 -07:00
Mohammad Shehar Yaar Tausif
af253aef18 bpf: fix order of args in call to bpf_map_kvcalloc
The original function call passed size of smap->bucket before the number of
buckets which raises the error 'calloc-transposed-args' on compilation.

Vlastimil Babka added:

The order of parameters can be traced back all the way to 6ac99e8f23
("bpf: Introduce bpf sk local storage") accross several refactorings,
and that's why the commit is used as a Fixes: tag.

In v6.10-rc1, a different commit 2c321f3f70 ("mm: change inlined
allocation helpers to account at the call site") however exposed the
order of args in a way that gcc-14 has enough visibility to start
warning about it, because (in !CONFIG_MEMCG case) bpf_map_kvcalloc is
then a macro alias for kvcalloc instead of a static inline wrapper.

To sum up the warning happens when the following conditions are all met:

- gcc-14 is used (didn't see it with gcc-13)
- commit 2c321f3f70 is present
- CONFIG_MEMCG is not enabled in .config
- CONFIG_WERROR turns this from a compiler warning to error

Fixes: 6ac99e8f23 ("bpf: Introduce bpf sk local storage")
Reviewed-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Mohammad Shehar Yaar Tausif <sheharyaar48@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20240710100521.15061-2-vbabka@suse.cz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-10 15:31:19 -07:00
Jinliang Zheng
cf3f9a593d mm: optimize the redundant loop of mm_update_owner_next()
When mm_update_owner_next() is racing with swapoff (try_to_unuse()) or
/proc or ptrace or page migration (get_task_mm()), it is impossible to
find an appropriate task_struct in the loop whose mm_struct is the same as
the target mm_struct.

If the above race condition is combined with the stress-ng-zombie and
stress-ng-dup tests, such a long loop can easily cause a Hard Lockup in
write_lock_irq() for tasklist_lock.

Recognize this situation in advance and exit early.

Link: https://lkml.kernel.org/r/20240620122123.3877432-1-alexjlzheng@tencent.com
Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tycho Andersen <tandersen@netflix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 12:29:24 -07:00
John Stultz
ddae0ca2a8 sched: Move psi_account_irqtime() out of update_rq_clock_task() hotpath
It was reported that in moving to 6.1, a larger then 10%
regression was seen in the performance of
clock_gettime(CLOCK_THREAD_CPUTIME_ID,...).

Using a simple reproducer, I found:
5.10:
100000000 calls in 24345994193 ns => 243.460 ns per call
100000000 calls in 24288172050 ns => 242.882 ns per call
100000000 calls in 24289135225 ns => 242.891 ns per call

6.1:
100000000 calls in 28248646742 ns => 282.486 ns per call
100000000 calls in 28227055067 ns => 282.271 ns per call
100000000 calls in 28177471287 ns => 281.775 ns per call

The cause of this was finally narrowed down to the addition of
psi_account_irqtime() in update_rq_clock_task(), in commit
52b1364ba0 ("sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ
pressure").

In my initial attempt to resolve this, I leaned towards moving
all accounting work out of the clock_gettime() call path, but it
wasn't very pretty, so it will have to wait for a later deeper
rework. Instead, Peter shared this approach:

Rework psi_account_irqtime() to use its own psi_irq_time base
for accounting, and move it out of the hotpath, calling it
instead from sched_tick() and __schedule().

In testing this, we found the importance of ensuring
psi_account_irqtime() is run under the rq_lock, which Johannes
Weiner helpfully explained, so also add some lockdep annotations
to make that requirement clear.

With this change the performance is back in-line with 5.10:
6.1+fix:
100000000 calls in 24297324597 ns => 242.973 ns per call
100000000 calls in 24318869234 ns => 243.189 ns per call
100000000 calls in 24291564588 ns => 242.916 ns per call

Reported-by: Jimmy Shiu <jimmyshiu@google.com>
Originally-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Qais Yousef <qyousef@layalina.io>
Link: https://lore.kernel.org/r/20240618215909.4099720-1-jstultz@google.com
2024-07-01 13:01:44 +02:00
Wander Lairson Costa
b58652db66 sched/deadline: Fix task_struct reference leak
During the execution of the following stress test with linux-rt:

stress-ng --cyclic 30 --timeout 30 --minimize --quiet

kmemleak frequently reported a memory leak concerning the task_struct:

unreferenced object 0xffff8881305b8000 (size 16136):
  comm "stress-ng", pid 614, jiffies 4294883961 (age 286.412s)
  object hex dump (first 32 bytes):
    02 40 00 00 00 00 00 00 00 00 00 00 00 00 00 00  .@..............
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  debug hex dump (first 16 bytes):
    53 09 00 00 00 00 00 00 00 00 00 00 00 00 00 00  S...............
  backtrace:
    [<00000000046b6790>] dup_task_struct+0x30/0x540
    [<00000000c5ca0f0b>] copy_process+0x3d9/0x50e0
    [<00000000ced59777>] kernel_clone+0xb0/0x770
    [<00000000a50befdc>] __do_sys_clone+0xb6/0xf0
    [<000000001dbf2008>] do_syscall_64+0x5d/0xf0
    [<00000000552900ff>] entry_SYSCALL_64_after_hwframe+0x6e/0x76

The issue occurs in start_dl_timer(), which increments the task_struct
reference count and sets a timer. The timer callback, dl_task_timer,
is supposed to decrement the reference count upon expiration. However,
if enqueue_task_dl() is called before the timer expires and cancels it,
the reference count is not decremented, leading to the leak.

This patch fixes the reference leak by ensuring the task_struct
reference count is properly decremented when the timer is canceled.

Fixes: feff2e65ef ("sched/deadline: Unthrottle PI boosted threads while enqueuing")
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/r/20240620125618.11419-1-wander@redhat.com
2024-07-01 13:01:44 +02:00
Josh Don
2feab2492d Revert "sched/fair: Make sure to try to detach at least one movable task"
This reverts commit b0defa7ae0.

b0defa7ae0 changed the load balancing logic to ignore env.max_loop if
all tasks examined to that point were pinned. The goal of the patch was
to make it more likely to be able to detach a task buried in a long list
of pinned tasks. However, this has the unfortunate side effect of
creating an O(n) iteration in detach_tasks(), as we now must fully
iterate every task on a cpu if all or most are pinned. Since this load
balance code is done with rq lock held, and often in softirq context, it
is very easy to trigger hard lockups. We observed such hard lockups with
a user who affined O(10k) threads to a single cpu.

When I discussed this with Vincent he initially suggested that we keep
the limit on the number of tasks to detach, but increase the number of
tasks we can search. However, after some back and forth on the mailing
list, he recommended we instead revert the original patch, as it seems
likely no one was actually getting hit by the original issue.

Fixes: b0defa7ae0 ("sched/fair: Make sure to try to detach at least one movable task")
Signed-off-by: Josh Don <joshdon@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240620214450.316280-1-joshdon@google.com
2024-07-01 13:01:43 +02:00
Linus Torvalds
3e334486ec TTY/Serial/Console fixes for 6.10-rc6
Here are a bunch of fixes/reverts for 6.10-rc6.  Include in here are:
   - revert the bunch of tty/serial/console changes that landed in -rc1
     that didn't quite work properly yet.  Everyone agreed to just revert
     them for now and will work on making them better for a future
     release instead of trying to quick fix the existing changes this
     late in the release cycle
   - 8250 driver port count bugfix
   - Other tiny serial port bugfixes for reported issues
 
 All of these have been in linux-next this week with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty / serial / console fixes from Greg KH:
 "Here are a bunch of fixes/reverts for 6.10-rc6.  Include in here are:

   - revert the bunch of tty/serial/console changes that landed in -rc1
     that didn't quite work properly yet.

     Everyone agreed to just revert them for now and will work on making
     them better for a future release instead of trying to quick fix the
     existing changes this late in the release cycle

   - 8250 driver port count bugfix

   - Other tiny serial port bugfixes for reported issues

  All of these have been in linux-next this week with no reported
  issues"

* tag 'tty-6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "printk: Save console options for add_preferred_console_match()"
  Revert "printk: Don't try to parse DEVNAME:0.0 console options"
  Revert "printk: Flag register_console() if console is set on command line"
  Revert "serial: core: Add support for DEVNAME:0.0 style naming for kernel console"
  Revert "serial: core: Handle serial console options"
  Revert "serial: 8250: Add preferred console in serial8250_isa_init_ports()"
  Revert "Documentation: kernel-parameters: Add DEVNAME:0.0 format for serial ports"
  Revert "serial: 8250: Fix add preferred console for serial8250_isa_init_ports()"
  Revert "serial: core: Fix ifdef for serial base console functions"
  serial: bcm63xx-uart: fix tx after conversion to uart_port_tx_limited()
  serial: core: introduce uart_port_tx_limited_flags()
  Revert "serial: core: only stop transmit when HW fifo is empty"
  serial: imx: set receiver level before starting uart
  tty: mcf: MCF54418 has 10 UARTS
  serial: 8250_omap: Implementation of Errata i2310
  tty: serial: 8250: Fix port count mismatch with the device
2024-06-30 08:57:43 -07:00
Linus Torvalds
3ffea9a7a6 - Fix "nosmp" and "maxcpus=0" after the parallel CPU bringup work went in and broke them
- Make sure CPU hotplug dynamic prepare states are actually executed
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Merge tag 'smp_urgent_for_v6.10_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull smp fixes from Borislav Petkov:

 - Fix "nosmp" and "maxcpus=0" after the parallel CPU bringup work went
   in and broke them

 - Make sure CPU hotplug dynamic prepare states are actually executed

* tag 'smp_urgent_for_v6.10_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu: Fix broken cmdline "nosmp" and "maxcpus=0"
  cpu/hotplug: Fix dynstate assignment in __cpuhp_setup_state_cpuslocked()
2024-06-30 08:41:42 -07:00
Linus Torvalds
03c8b0bd46 - Warn when an hrtimer doesn't get a callback supplied
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Merge tag 'timers_urgent_for_v6.10_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fix from Borislav Petkov:

 - Warn when an hrtimer doesn't get a callback supplied

* tag 'timers_urgent_for_v6.10_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Prevent queuing of hrtimer without a function callback
2024-06-30 08:31:08 -07:00
Linus Torvalds
adfbe3640b asm-generic fixes for 6.10
These are some bugfixes for system call ABI issues I found while
 working on a cleanup series. None of these are urgent since these
 bugs have gone unnoticed for many years, but I think we probably
 want to backport them all to stable kernels, so it makes sense
 to have the fixes included as early as possible.
 
 One more fix addresses a compile-time warning in kallsyms that was
 uncovered by a patch I did to enable additional warnings in 6.10. I had
 mistakenly thought that this fix was already merged through the module
 tree, but as Geert pointed out it was still missing.
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Merge tag 'asm-generic-fixes-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull asm-generic fixes from Arnd Bergmann:
 "These are some bugfixes for system call ABI issues I found while
  working on a cleanup series. None of these are urgent since these bugs
  have gone unnoticed for many years, but I think we probably want to
  backport them all to stable kernels, so it makes sense to have the
  fixes included as early as possible.

  One more fix addresses a compile-time warning in kallsyms that was
  uncovered by a patch I did to enable additional warnings in 6.10. I
  had mistakenly thought that this fix was already merged through the
  module tree, but as Geert pointed out it was still missing"

* tag 'asm-generic-fixes-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  kallsyms: rework symbol lookup return codes
  linux/syscalls.h: add missing __user annotations
  syscalls: mmap(): use unsigned offset type consistently
  s390: remove native mmap2() syscall
  hexagon: fix fadvise64_64 calling conventions
  csky, hexagon: fix broken sys_sync_file_range
  sh: rework sync_file_range ABI
  powerpc: restore some missing spu syscalls
  parisc: use generic sys_fanotify_mark implementation
  parisc: use correct compat recv/recvfrom syscalls
  sparc: fix compat recv/recvfrom syscalls
  sparc: fix old compat_sys_select()
  syscalls: fix compat_sys_io_pgetevents_time64 usage
  ftruncate: pass a signed offset
2024-06-27 10:53:52 -07:00
Linus Torvalds
fd19d4a492 Including fixes from can, bpf and netfilter.
Current release - regressions:
 
   - core: add softirq safety to netdev_rename_lock
 
   - tcp: fix tcp_rcv_fastopen_synack() to enter TCP_CA_Loss for failed TFO
 
   - batman-adv: fix RCU race at module unload time
 
 Current release - new code bugs:
 
 Previous releases - regressions:
 
   - openvswitch: get related ct labels from its master if it is not confirmed
 
   - eth: bonding: fix incorrect software timestamping report
 
   - eth: mlxsw: fix memory corruptions on spectrum-4 systems
 
   - eth: ionic: use dev_consume_skb_any outside of napi
 
 Previous releases - always broken:
 
   - netfilter: fully validate NFT_DATA_VALUE on store to data registers
 
   - unix: several fixes for OoB data
 
   - tcp: fix race for duplicate reqsk on identical SYN
 
   - bpf:
     - fix may_goto with negative offset.
     - fix the corner case with may_goto and jump to the 1st insn.
     - fix overrunning reservations in ringbuf
 
   - can:
     - j1939: recover socket queue on CAN bus error during BAM transmission
     - mcp251xfd: fix infinite loop when xmit fails
 
   - dsa: microchip: monitor potential faults in half-duplex mode
 
   - eth: vxlan: pull inner IP header in vxlan_xmit_one()
 
   - eth: ionic: fix kernel panic due to multi-buffer handling
 
 Misc:
 
   - selftest: unix tests refactor and a lot of new cases added
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from can, bpf and netfilter.

  There are a bunch of regressions addressed here, but hopefully nothing
  spectacular. We are still waiting the driver fix from Intel, mentioned
  by Jakub in the previous networking pull.

  Current release - regressions:

   - core: add softirq safety to netdev_rename_lock

   - tcp: fix tcp_rcv_fastopen_synack() to enter TCP_CA_Loss for failed
     TFO

   - batman-adv: fix RCU race at module unload time

  Previous releases - regressions:

   - openvswitch: get related ct labels from its master if it is not
     confirmed

   - eth: bonding: fix incorrect software timestamping report

   - eth: mlxsw: fix memory corruptions on spectrum-4 systems

   - eth: ionic: use dev_consume_skb_any outside of napi

  Previous releases - always broken:

   - netfilter: fully validate NFT_DATA_VALUE on store to data registers

   - unix: several fixes for OoB data

   - tcp: fix race for duplicate reqsk on identical SYN

   - bpf:
       - fix may_goto with negative offset
       - fix the corner case with may_goto and jump to the 1st insn
       - fix overrunning reservations in ringbuf

   - can:
       - j1939: recover socket queue on CAN bus error during BAM
         transmission
       - mcp251xfd: fix infinite loop when xmit fails

   - dsa: microchip: monitor potential faults in half-duplex mode

   - eth: vxlan: pull inner IP header in vxlan_xmit_one()

   - eth: ionic: fix kernel panic due to multi-buffer handling

  Misc:

   - selftest: unix tests refactor and a lot of new cases added"

* tag 'net-6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (61 commits)
  net: mana: Fix possible double free in error handling path
  selftest: af_unix: Check SIOCATMARK after every send()/recv() in msg_oob.c.
  af_unix: Fix wrong ioctl(SIOCATMARK) when consumed OOB skb is at the head.
  selftest: af_unix: Check EPOLLPRI after every send()/recv() in msg_oob.c
  selftest: af_unix: Check SIGURG after every send() in msg_oob.c
  selftest: af_unix: Add SO_OOBINLINE test cases in msg_oob.c
  af_unix: Don't stop recv() at consumed ex-OOB skb.
  selftest: af_unix: Add non-TCP-compliant test cases in msg_oob.c.
  af_unix: Don't stop recv(MSG_DONTWAIT) if consumed OOB skb is at the head.
  af_unix: Stop recv(MSG_PEEK) at consumed OOB skb.
  selftest: af_unix: Add msg_oob.c.
  selftest: af_unix: Remove test_unix_oob.c.
  tracing/net_sched: NULL pointer dereference in perf_trace_qdisc_reset()
  netfilter: nf_tables: fully validate NFT_DATA_VALUE on store to data registers
  net: usb: qmi_wwan: add Telit FN912 compositions
  tcp: fix tcp_rcv_fastopen_synack() to enter TCP_CA_Loss for failed TFO
  ionic: use dev_consume_skb_any outside of napi
  net: dsa: microchip: fix wrong register write when masking interrupt
  Fix race for duplicate reqsk on identical SYN
  ibmvnic: Add tx check to prevent skb leak
  ...
2024-06-27 10:05:35 -07:00
Arnd Bergmann
7e1f4eb9a6 kallsyms: rework symbol lookup return codes
Building with W=1 in some configurations produces a false positive
warning for kallsyms:

kernel/kallsyms.c: In function '__sprint_symbol.isra':
kernel/kallsyms.c:503:17: error: 'strcpy' source argument is the same as destination [-Werror=restrict]
  503 |                 strcpy(buffer, name);
      |                 ^~~~~~~~~~~~~~~~~~~~

This originally showed up while building with -O3, but later started
happening in other configurations as well, depending on inlining
decisions. The underlying issue is that the local 'name' variable is
always initialized to the be the same as 'buffer' in the called functions
that fill the buffer, which gcc notices while inlining, though it could
see that the address check always skips the copy.

The calling conventions here are rather unusual, as all of the internal
lookup functions (bpf_address_lookup, ftrace_mod_address_lookup,
ftrace_func_address_lookup, module_address_lookup and
kallsyms_lookup_buildid) already use the provided buffer and either return
the address of that buffer to indicate success, or NULL for failure,
but the callers are written to also expect an arbitrary other buffer
to be returned.

Rework the calling conventions to return the length of the filled buffer
instead of its address, which is simpler and easier to follow as well
as avoiding the warning. Leave only the kallsyms_lookup() calling conventions
unchanged, since that is called from 16 different functions and
adapting this would be a much bigger change.

Link: https://lore.kernel.org/lkml/20200107214042.855757-1-arnd@arndb.de/
Link: https://lore.kernel.org/lkml/20240326130647.7bfb1d92@gandalf.local.home/
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-06-27 17:43:40 +02:00
Linus Torvalds
24ca36a562 workqueue: Fixes for v6.10-rc5
Two patches to fix kworker name formatting.
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Merge tag 'wq-for-6.10-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue fixes from Tejun Heo:
 "Two patches to fix kworker name formatting"

* tag 'wq-for-6.10-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Increase worker desc's length to 32
  workqueue: Refactor worker ID formatting and make wq_worker_comm() use full ID string
2024-06-26 15:01:33 -07:00
Phil Chang
5a830bbce3 hrtimer: Prevent queuing of hrtimer without a function callback
The hrtimer function callback must not be NULL. It has to be specified by
the call side but it is not validated by the hrtimer code. When a hrtimer
is queued without a function callback, the kernel crashes with a null
pointer dereference when trying to execute the callback in __run_hrtimer().

Introduce a validation before queuing the hrtimer in
hrtimer_start_range_ns().

[anna-maria: Rephrase commit message]

Signed-off-by: Phil Chang <phil.chang@mediatek.com>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
2024-06-25 16:54:27 +02:00
Arnd Bergmann
d3882564a7 syscalls: fix compat_sys_io_pgetevents_time64 usage
Using sys_io_pgetevents() as the entry point for compat mode tasks
works almost correctly, but misses the sign extension for the min_nr
and nr arguments.

This was addressed on parisc by switching to
compat_sys_io_pgetevents_time64() in commit 6431e92fc8 ("parisc:
io_pgetevents_time64() needs compat syscall in 32-bit compat mode"),
as well as by using more sophisticated system call wrappers on x86 and
s390. However, arm64, mips, powerpc, sparc and riscv still have the
same bug.

Change all of them over to use compat_sys_io_pgetevents_time64()
like parisc already does. This was clearly the intention when the
function was originally added, but it got hooked up incorrectly in
the tables.

Cc: stable@vger.kernel.org
Fixes: 48166e6ea4 ("y2038: add 64-bit time_t syscalls to all 32-bit architectures")
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-06-25 15:57:20 +02:00
Greg Kroah-Hartman
cc8d5a2f09 Revert "printk: Save console options for add_preferred_console_match()"
This reverts commit f03e8c1060.

Let's roll back all of the serial core and printk console changes that
went into 6.10-rc1 as there still are problems with them that need to be
sorted out.

Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1
Reported-by: Petr Mladek <pmladek@suse.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-25 07:58:10 +02:00
Greg Kroah-Hartman
64f9f010c6 Revert "printk: Don't try to parse DEVNAME:0.0 console options"
This reverts commit 8a831c584e.

Let's roll back all of the serial core and printk console changes that
went into 6.10-rc1 as there still are problems with them that need to be
sorted out.

Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1
Reported-by: Petr Mladek <pmladek@suse.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-25 07:58:07 +02:00
Greg Kroah-Hartman
deb091cb05 Revert "printk: Flag register_console() if console is set on command line"
This reverts commit b73c9cbe4f.

Let's roll back all of the serial core and printk console changes that
went into 6.10-rc1 as there still are problems with them that need to be
sorted out.

Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1
Reported-by: Petr Mladek <pmladek@suse.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-25 07:58:03 +02:00
Jakub Kicinski
482000cf7f bpf-for-netdev
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Merge tag 'for-netdev' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2024-06-24

We've added 12 non-merge commits during the last 10 day(s) which contain
a total of 10 files changed, 412 insertions(+), 16 deletions(-).

The main changes are:

1) Fix a BPF verifier issue validating may_goto with a negative offset,
   from Alexei Starovoitov.

2) Fix a BPF verifier validation bug with may_goto combined with jump to
   the first instruction, also from Alexei Starovoitov.

3) Fix a bug with overrunning reservations in BPF ring buffer,
   from Daniel Borkmann.

4) Fix a bug in BPF verifier due to missing proper var_off setting related
   to movsx instruction, from Yonghong Song.

5) Silence unnecessary syzkaller-triggered warning in __xdp_reg_mem_model(),
   from Daniil Dulov.

* tag 'for-netdev' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  xdp: Remove WARN() from __xdp_reg_mem_model()
  selftests/bpf: Add tests for may_goto with negative offset.
  bpf: Fix may_goto with negative offset.
  selftests/bpf: Add more ring buffer test coverage
  bpf: Fix overrunning reservations in ringbuf
  selftests/bpf: Tests with may_goto and jumps to the 1st insn
  bpf: Fix the corner case with may_goto and jump to the 1st insn.
  bpf: Update BPF LSM maintainer list
  bpf: Fix remap of arena.
  selftests/bpf: Add a few tests to cover
  bpf: Add missed var_off setting in coerce_subreg_to_size_sx()
  bpf: Add missed var_off setting in set_sext32_default_val()
====================

Link: https://patch.msgid.link/20240624124330.8401-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-24 18:15:22 -07:00
Alexei Starovoitov
2b2efe1937 bpf: Fix may_goto with negative offset.
Zac's syzbot crafted a bpf prog that exposed two bugs in may_goto.
The 1st bug is the way may_goto is patched. When offset is negative
it should be patched differently.
The 2nd bug is in the verifier:
when current state may_goto_depth is equal to visited state may_goto_depth
it means there is an actual infinite loop. It's not correct to prune
exploration of the program at this point.
Note, that this check doesn't limit the program to only one may_goto insn,
since 2nd and any further may_goto will increment may_goto_depth only
in the queued state pushed for future exploration. The current state
will have may_goto_depth == 0 regardless of number of may_goto insns
and the verifier has to explore the program until bpf_exit.

Fixes: 011832b97b ("bpf: Introduce may_goto instruction")
Reported-by: Zac Ecob <zacecob@protonmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Closes: https://lore.kernel.org/bpf/CAADnVQL-15aNp04-cyHRn47Yv61NXfYyhopyZtUyxNojUZUXpA@mail.gmail.com/
Link: https://lore.kernel.org/bpf/20240619235355.85031-1-alexei.starovoitov@gmail.com
2024-06-24 13:44:02 +02:00
Huacai Chen
6ef8eb5125 cpu: Fix broken cmdline "nosmp" and "maxcpus=0"
After the rework of "Parallel CPU bringup", the cmdline "nosmp" and
"maxcpus=0" parameters are not working anymore. These parameters set
setup_max_cpus to zero and that's handed to bringup_nonboot_cpus().

The code there does a decrement before checking for zero, which brings it
into the negative space and brings up all CPUs.

Add a zero check at the beginning of the function to prevent this.

[ tglx: Massaged change log ]

Fixes: 18415f33e2 ("cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE")
Fixes: 06c6796e03 ("cpu/hotplug: Fix off by one in cpuhp_bringup_mask()")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240618081336.3996825-1-chenhuacai@loongson.cn
2024-06-23 20:04:14 +02:00
Daniel Borkmann
cfa1a2329a bpf: Fix overrunning reservations in ringbuf
The BPF ring buffer internally is implemented as a power-of-2 sized circular
buffer, with two logical and ever-increasing counters: consumer_pos is the
consumer counter to show which logical position the consumer consumed the
data, and producer_pos which is the producer counter denoting the amount of
data reserved by all producers.

Each time a record is reserved, the producer that "owns" the record will
successfully advance producer counter. In user space each time a record is
read, the consumer of the data advanced the consumer counter once it finished
processing. Both counters are stored in separate pages so that from user
space, the producer counter is read-only and the consumer counter is read-write.

One aspect that simplifies and thus speeds up the implementation of both
producers and consumers is how the data area is mapped twice contiguously
back-to-back in the virtual memory, allowing to not take any special measures
for samples that have to wrap around at the end of the circular buffer data
area, because the next page after the last data page would be first data page
again, and thus the sample will still appear completely contiguous in virtual
memory.

Each record has a struct bpf_ringbuf_hdr { u32 len; u32 pg_off; } header for
book-keeping the length and offset, and is inaccessible to the BPF program.
Helpers like bpf_ringbuf_reserve() return `(void *)hdr + BPF_RINGBUF_HDR_SZ`
for the BPF program to use. Bing-Jhong and Muhammad reported that it is however
possible to make a second allocated memory chunk overlapping with the first
chunk and as a result, the BPF program is now able to edit first chunk's
header.

For example, consider the creation of a BPF_MAP_TYPE_RINGBUF map with size
of 0x4000. Next, the consumer_pos is modified to 0x3000 /before/ a call to
bpf_ringbuf_reserve() is made. This will allocate a chunk A, which is in
[0x0,0x3008], and the BPF program is able to edit [0x8,0x3008]. Now, lets
allocate a chunk B with size 0x3000. This will succeed because consumer_pos
was edited ahead of time to pass the `new_prod_pos - cons_pos > rb->mask`
check. Chunk B will be in range [0x3008,0x6010], and the BPF program is able
to edit [0x3010,0x6010]. Due to the ring buffer memory layout mentioned
earlier, the ranges [0x0,0x4000] and [0x4000,0x8000] point to the same data
pages. This means that chunk B at [0x4000,0x4008] is chunk A's header.
bpf_ringbuf_submit() / bpf_ringbuf_discard() use the header's pg_off to then
locate the bpf_ringbuf itself via bpf_ringbuf_restore_from_rec(). Once chunk
B modified chunk A's header, then bpf_ringbuf_commit() refers to the wrong
page and could cause a crash.

Fix it by calculating the oldest pending_pos and check whether the range
from the oldest outstanding record to the newest would span beyond the ring
buffer size. If that is the case, then reject the request. We've tested with
the ring buffer benchmark in BPF selftests (./benchs/run_bench_ringbufs.sh)
before/after the fix and while it seems a bit slower on some benchmarks, it
is still not significantly enough to matter.

Fixes: 457f44363a ("bpf: Implement BPF ring buffer and verifier support for it")
Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Reported-by: Muhammad Ramdhan <ramdhan@starlabs.sg>
Co-developed-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Co-developed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240621140828.18238-1-daniel@iogearbox.net
2024-06-21 13:04:21 -07:00
Alexei Starovoitov
5337ac4c9b bpf: Fix the corner case with may_goto and jump to the 1st insn.
When the following program is processed by the verifier:
L1: may_goto L2
    goto L1
L2: w0 = 0
    exit

the may_goto insn is first converted to:
L1: r11 = *(u64 *)(r10 -8)
    if r11 == 0x0 goto L2
    r11 -= 1
    *(u64 *)(r10 -8) = r11
    goto L1
L2: w0 = 0
    exit

then later as the last step the verifier inserts:
  *(u64 *)(r10 -8) = BPF_MAX_LOOPS
as the first insn of the program to initialize loop count.

When the first insn happens to be a branch target of some jmp the
bpf_patch_insn_data() logic will produce:
L1: *(u64 *)(r10 -8) = BPF_MAX_LOOPS
    r11 = *(u64 *)(r10 -8)
    if r11 == 0x0 goto L2
    r11 -= 1
    *(u64 *)(r10 -8) = r11
    goto L1
L2: w0 = 0
    exit

because instruction patching adjusts all jmps and calls, but for this
particular corner case it's incorrect and the L1 label should be one
instruction down, like:
    *(u64 *)(r10 -8) = BPF_MAX_LOOPS
L1: r11 = *(u64 *)(r10 -8)
    if r11 == 0x0 goto L2
    r11 -= 1
    *(u64 *)(r10 -8) = r11
    goto L1
L2: w0 = 0
    exit

and that's what this patch is fixing.
After bpf_patch_insn_data() call adjust_jmp_off() to adjust all jmps
that point to newly insert BPF_ST insn to point to insn after.

Note that bpf_patch_insn_data() cannot easily be changed to accommodate
this logic, since jumps that point before or after a sequence of patched
instructions have to be adjusted with the full length of the patch.

Conceptually it's somewhat similar to "insert" of instructions between other
instructions with weird semantics. Like "insert" before 1st insn would require
adjustment of CALL insns to point to newly inserted 1st insn, but not an
adjustment JMP insns that point to 1st, yet still adjusting JMP insns that
cross over 1st insn (point to insn before or insn after), hence use simple
adjust_jmp_off() logic to fix this corner case. Ideally bpf_patch_insn_data()
would have an auxiliary info to say where 'the start of newly inserted patch
is', but it would be too complex for backport.

Fixes: 011832b97b ("bpf: Introduce may_goto instruction")
Reported-by: Zac Ecob <zacecob@protonmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Closes: https://lore.kernel.org/bpf/CAADnVQJ_WWx8w4b=6Gc2EpzAjgv+6A0ridnMz2TvS2egj4r3Gw@mail.gmail.com/
Link: https://lore.kernel.org/bpf/20240619011859.79334-1-alexei.starovoitov@gmail.com
2024-06-21 20:18:40 +02:00
Linus Torvalds
d5a7fc58da Including fixes from wireless, bpf and netfilter.
Current release - regressions:
 
  - ipv6: bring NLM_DONE out to a separate recv() again
 
 Current release - new code bugs:
 
  - wifi: cfg80211: wext: set ssids=NULL for passive scans via old wext API
 
 Previous releases - regressions:
 
  - wifi: mac80211: fix monitor channel setting with chanctx emulation
    (probably most awaited of the fixes in this PR, tracked by Thorsten)
 
  - usb: ax88179_178a: bring back reset on init, if PHY is disconnected
 
  - bpf: fix UML x86_64 compile failure with BPF
 
  - bpf: avoid splat in pskb_pull_reason(), sanity check added can be hit
    with malicious BPF
 
  - eth: mvpp2: use slab_build_skb() for packets in slab, driver was
    missed during API refactoring
 
  - wifi: iwlwifi: add missing unlock of mvm mutex
 
 Previous releases - always broken:
 
  - ipv6: add a number of missing null-checks for in6_dev_get(), in case
    IPv6 disabling races with the datapath
 
  - bpf: fix reg_set_min_max corruption of fake_reg
 
  - sched: act_ct: add netns as part of the key of tcf_ct_flow_table
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-6.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from wireless, bpf and netfilter.

  Happy summer solstice! The line count is a bit inflated by a selftest
  and update to a driver's FW interface header, in reality this is
  slightly below average for us. We are expecting one driver fix from
  Intel, but there are no big known issues.

  Current release - regressions:

   - ipv6: bring NLM_DONE out to a separate recv() again

  Current release - new code bugs:

   - wifi: cfg80211: wext: set ssids=NULL for passive scans via old wext API

  Previous releases - regressions:

   - wifi: mac80211: fix monitor channel setting with chanctx emulation
     (probably most awaited of the fixes in this PR, tracked by Thorsten)

   - usb: ax88179_178a: bring back reset on init, if PHY is disconnected

   - bpf: fix UML x86_64 compile failure with BPF

   - bpf: avoid splat in pskb_pull_reason(), sanity check added can be hit
     with malicious BPF

   - eth: mvpp2: use slab_build_skb() for packets in slab, driver was
     missed during API refactoring

   - wifi: iwlwifi: add missing unlock of mvm mutex

  Previous releases - always broken:

   - ipv6: add a number of missing null-checks for in6_dev_get(), in case
     IPv6 disabling races with the datapath

   - bpf: fix reg_set_min_max corruption of fake_reg

   - sched: act_ct: add netns as part of the key of tcf_ct_flow_table"

* tag 'net-6.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (63 commits)
  net: usb: rtl8150 fix unintiatilzed variables in rtl8150_get_link_ksettings
  selftests: virtio_net: add forgotten config options
  bnxt_en: Restore PTP tx_avail count in case of skb_pad() error
  bnxt_en: Set TSO max segs on devices with limits
  bnxt_en: Update firmware interface to 1.10.3.44
  net: stmmac: Assign configured channel value to EXTTS event
  net: do not leave a dangling sk pointer, when socket creation fails
  net/tcp_ao: Don't leak ao_info on error-path
  ice: Fix VSI list rule with ICE_SW_LKUP_LAST type
  ipv6: bring NLM_DONE out to a separate recv() again
  selftests: add selftest for the SRv6 End.DX6 behavior with netfilter
  selftests: add selftest for the SRv6 End.DX4 behavior with netfilter
  netfilter: move the sysctl nf_hooks_lwtunnel into the netfilter core
  seg6: fix parameter passing when calling NF_HOOK() in End.DX4 and End.DX6 behaviors
  netfilter: ipset: Fix suspicious rcu_dereference_protected()
  selftests: openvswitch: Set value to nla flags.
  octeontx2-pf: Fix linking objects into multiple modules
  octeontx2-pf: Add error handling to VLAN unoffload handling
  virtio_net: fixing XDP for fully checksummed packets handling
  virtio_net: checksum offloading handling fix
  ...
2024-06-20 10:49:50 -07:00
Linus Torvalds
e5b3efbe1a Probes fixes for v6.10-rc4:
- Restrict gen-API tests for synthetic and kprobe events to only be built as
   modules, as they generate dynamic events that cannot be removed, causing
   ftracetest and startup selftests to fail.
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Merge tag 'probes-fixes-v6.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fix from Masami Hiramatsu:

 - Restrict gen-API tests for synthetic and kprobe events to only be
   built as modules, as they generate dynamic events that cannot be
   removed, causing ftracetest and startup selftests to fail

* tag 'probes-fixes-v6.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Build event generation tests only as modules
2024-06-19 10:29:49 -07:00
Alexei Starovoitov
b90d77e5fd bpf: Fix remap of arena.
The bpf arena logic didn't account for mremap operation. Add a refcnt for
multiple mmap events to prevent use-after-free in arena_vm_close.

Fixes: 317460317a ("bpf: Introduce bpf_arena.")
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Barret Rhoden <brho@google.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Closes: https://lore.kernel.org/bpf/Zmuw29IhgyPNKnIM@xpf.sh.intel.com
Link: https://lore.kernel.org/bpf/20240617171812.76634-1-alexei.starovoitov@gmail.com
2024-06-18 17:19:46 +02:00
Linus Torvalds
3d54351c64 lsm/stable-6.10 PR 20240617
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Merge tag 'lsm-pr-20240617' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm

Pull lsm fix from Paul Moore:
 "A single LSM/IMA patch to fix a problem caused by sleeping while in a
  RCU critical section"

* tag 'lsm-pr-20240617' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
  ima: Avoid blocking in RCU read-side critical section
2024-06-17 18:35:12 -07:00
Linus Torvalds
e6b324fbf2 19 hotfixes, 8 of which are cc:stable.
Mainly MM singleton fixes.  And a couple of ocfs2 regression fixes.
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Merge tag 'mm-hotfixes-stable-2024-06-17-11-43' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "Mainly MM singleton fixes. And a couple of ocfs2 regression fixes"

* tag 'mm-hotfixes-stable-2024-06-17-11-43' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  kcov: don't lose track of remote references during softirqs
  mm: shmem: fix getting incorrect lruvec when replacing a shmem folio
  mm/debug_vm_pgtable: drop RANDOM_ORVALUE trick
  mm: fix possible OOB in numa_rebuild_large_mapping()
  mm/migrate: fix kernel BUG at mm/compaction.c:2761!
  selftests: mm: make map_fixed_noreplace test names stable
  mm/memfd: add documentation for MFD_NOEXEC_SEAL MFD_EXEC
  mm: mmap: allow for the maximum number of bits for randomizing mmap_base by default
  gcov: add support for GCC 14
  zap_pid_ns_processes: clear TIF_NOTIFY_SIGNAL along with TIF_SIGPENDING
  mm: huge_memory: fix misused mapping_large_folio_support() for anon folios
  lib/alloc_tag: fix RCU imbalance in pgalloc_tag_get()
  lib/alloc_tag: do not register sysctl interface when CONFIG_SYSCTL=n
  MAINTAINERS: remove Lorenzo as vmalloc reviewer
  Revert "mm: init_mlocked_on_free_v3"
  mm/page_table_check: fix crash on ZONE_DEVICE
  gcc: disable '-Warray-bounds' for gcc-9
  ocfs2: fix NULL pointer dereference in ocfs2_abort_trigger()
  ocfs2: fix NULL pointer dereference in ocfs2_journal_dirty()
2024-06-17 12:30:07 -07:00
Yonghong Song
44b7f7151d bpf: Add missed var_off setting in coerce_subreg_to_size_sx()
In coerce_subreg_to_size_sx(), for the case where upper
sign extension bits are the same for smax32 and smin32
values, we missed to setup properly. This is especially
problematic if both smax32 and smin32's sign extension
bits are 1.

The following is a simple example illustrating the inconsistent
verifier states due to missed var_off:

  0: (85) call bpf_get_prandom_u32#7    ; R0_w=scalar()
  1: (bf) r3 = r0                       ; R0_w=scalar(id=1) R3_w=scalar(id=1)
  2: (57) r3 &= 15                      ; R3_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=15,var_off=(0x0; 0xf))
  3: (47) r3 |= 128                     ; R3_w=scalar(smin=umin=smin32=umin32=128,smax=umax=smax32=umax32=143,var_off=(0x80; 0xf))
  4: (bc) w7 = (s8)w3
  REG INVARIANTS VIOLATION (alu): range bounds violation u64=[0xffffff80, 0x8f] s64=[0xffffff80, 0x8f]
    u32=[0xffffff80, 0x8f] s32=[0x80, 0xffffff8f] var_off=(0x80, 0xf)

The var_off=(0x80, 0xf) is not correct, and the correct one should
be var_off=(0xffffff80; 0xf) since from insn 3, we know that at
insn 4, the sign extension bits will be 1. This patch fixed this
issue by setting var_off properly.

Fixes: 8100928c88 ("bpf: Support new sign-extension mov insns")
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240615174632.3995278-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-17 10:45:46 -07:00
Yonghong Song
380d5f89a4 bpf: Add missed var_off setting in set_sext32_default_val()
Zac reported a verification failure and Alexei reproduced the issue
with a simple reproducer ([1]). The verification failure is due to missed
setting for var_off.

The following is the reproducer in [1]:
  0: R1=ctx() R10=fp0
  0: (71) r3 = *(u8 *)(r10 -387)        ;
     R3_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff)) R10=fp0
  1: (bc) w7 = (s8)w3                   ;
     R3_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff))
     R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=127,var_off=(0x0; 0x7f))
  2: (36) if w7 >= 0x2533823b goto pc-3
     mark_precise: frame0: last_idx 2 first_idx 0 subseq_idx -1
     mark_precise: frame0: regs=r7 stack= before 1: (bc) w7 = (s8)w3
     mark_precise: frame0: regs=r3 stack= before 0: (71) r3 = *(u8 *)(r10 -387)
  2: R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=127,var_off=(0x0; 0x7f))
  3: (b4) w0 = 0                        ; R0_w=0
  4: (95) exit

Note that after insn 1, the var_off for R7 is (0x0; 0x7f). This is not correct
since upper 24 bits of w7 could be 0 or 1. So correct var_off should be
(0x0; 0xffffffff). Missing var_off setting in set_sext32_default_val() caused later
incorrect analysis in zext_32_to_64(dst_reg) and reg_bounds_sync(dst_reg).

To fix the issue, set var_off correctly in set_sext32_default_val(). The correct
reg state after insn 1 becomes:
  1: (bc) w7 = (s8)w3                   ;
     R3_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff))
     R7_w=scalar(smin=0,smax=umax=0xffffffff,smin32=-128,smax32=127,var_off=(0x0; 0xffffffff))
and at insn 2, the verifier correctly determines either branch is possible.

  [1] https://lore.kernel.org/bpf/CAADnVQLPU0Shz7dWV4bn2BgtGdxN3uFHPeobGBA72tpg5Xoykw@mail.gmail.com/

Fixes: 8100928c88 ("bpf: Support new sign-extension mov insns")
Reported-by: Zac Ecob <zacecob@protonmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240615174626.3994813-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-17 10:45:46 -07:00
Yuntao Wang
932d847639 cpu/hotplug: Fix dynstate assignment in __cpuhp_setup_state_cpuslocked()
Commit 4205e4786d ("cpu/hotplug: Provide dynamic range for prepare
stage") added a dynamic range for the prepare states, but did not handle
the assignment of the dynstate variable in __cpuhp_setup_state_cpuslocked().

This causes the corresponding startup callback not to be invoked when
calling __cpuhp_setup_state_cpuslocked() with the CPUHP_BP_PREPARE_DYN
parameter, even though it should be.

Currently, the users of __cpuhp_setup_state_cpuslocked(), for one reason or
another, have not triggered this bug.

Fixes: 4205e4786d ("cpu/hotplug: Provide dynamic range for prepare stage")
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240515134554.427071-1-ytcoode@gmail.com
2024-06-17 15:08:04 +02:00
Aleksandr Nogikh
01c8f9806b kcov: don't lose track of remote references during softirqs
In kcov_remote_start()/kcov_remote_stop(), we swap the previous KCOV
metadata of the current task into a per-CPU variable.  However, the
kcov_mode_enabled(mode) check is not sufficient in the case of remote KCOV
coverage: current->kcov_mode always remains KCOV_MODE_DISABLED for remote
KCOV objects.

If the original task that has invoked the KCOV_REMOTE_ENABLE ioctl happens
to get interrupted and kcov_remote_start() is called, it ultimately leads
to kcov_remote_stop() NOT restoring the original KCOV reference.  So when
the task exits, all registered remote KCOV handles remain active forever.

The most uncomfortable effect (at least for syzkaller) is that the bug
prevents the reuse of the same /sys/kernel/debug/kcov descriptor.  If
we obtain it in the parent process and then e.g.  drop some
capabilities and continuously fork to execute individual programs, at
some point current->kcov of the forked process is lost,
kcov_task_exit() takes no action, and all KCOV_REMOTE_ENABLE ioctls
calls from subsequent forks fail.

And, yes, the efficiency is also affected if we keep on losing remote
kcov objects.
a) kcov_remote_map keeps on growing forever.
b) (If I'm not mistaken), we're also not freeing the memory referenced
by kcov->area.

Fix it by introducing a special kcov_mode that is assigned to the task
that owns a KCOV remote object.  It makes kcov_mode_enabled() return true
and yet does not trigger coverage collection in __sanitizer_cov_trace_pc()
and write_comp_data().

[nogikh@google.com: replace WRITE_ONCE() with an ordinary assignment]
  Link: https://lkml.kernel.org/r/20240614171221.2837584-1-nogikh@google.com
Link: https://lkml.kernel.org/r/20240611133229.527822-1-nogikh@google.com
Fixes: 5ff3b30ab5 ("kcov: collect coverage from interrupts")
Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marco Elver <elver@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-15 10:43:08 -07:00
Peter Oberparleiter
c1558bc57b gcov: add support for GCC 14
Using gcov on kernels compiled with GCC 14 results in truncated 16-byte
long .gcda files with no usable data.  To fix this, update GCOV_COUNTERS
to match the value defined by GCC 14.

Tested with GCC versions 14.1.0 and 13.2.0.

Link: https://lkml.kernel.org/r/20240610092743.1609845-1-oberpar@linux.ibm.com
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reported-by: Allison Henderson <allison.henderson@oracle.com>
Reported-by: Chuck Lever III <chuck.lever@oracle.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-15 10:43:06 -07:00
Oleg Nesterov
7fea700e04 zap_pid_ns_processes: clear TIF_NOTIFY_SIGNAL along with TIF_SIGPENDING
kernel_wait4() doesn't sleep and returns -EINTR if there is no
eligible child and signal_pending() is true.

That is why zap_pid_ns_processes() clears TIF_SIGPENDING but this is not
enough, it should also clear TIF_NOTIFY_SIGNAL to make signal_pending()
return false and avoid a busy-wait loop.

Link: https://lkml.kernel.org/r/20240608120616.GB7947@redhat.com
Fixes: 12db8b6900 ("entry: Add support for TIF_NOTIFY_SIGNAL")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Rachel Menge <rachelmenge@linux.microsoft.com>
Closes: https://lore.kernel.org/all/1386cd49-36d0-4a5c-85e9-bc42056a5a38@linux.microsoft.com/
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Tested-by: Wei Fu <fuweid89@gmail.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: Allen Pais <apais@linux.microsoft.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Joel Granados <j.granados@samsung.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Zqiang <qiang.zhang1211@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-15 10:43:06 -07:00
Jakub Kicinski
c64da10adb bpf-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2024-06-14

We've added 8 non-merge commits during the last 2 day(s) which contain
a total of 9 files changed, 92 insertions(+), 11 deletions(-).

The main changes are:

1) Silence a syzkaller splat under CONFIG_DEBUG_NET=y in pskb_pull_reason()
   triggered via __bpf_try_make_writable(), from Florian Westphal.

2) Fix removal of kfuncs during linking phase which then throws a kernel
   build warning via resolve_btfids about unresolved symbols,
   from Tony Ambardar.

3) Fix a UML x86_64 compilation failure from BPF as pcpu_hot symbol
   is not available on User Mode Linux, from Maciej Żenczykowski.

4) Fix a register corruption in reg_set_min_max triggering an invariant
   violation in BPF verifier, from Daniel Borkmann.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Harden __bpf_kfunc tag against linker kfunc removal
  compiler_types.h: Define __retain for __attribute__((__retain__))
  bpf: Avoid splat in pskb_pull_reason
  bpf: fix UML x86_64 compile failure
  selftests/bpf: Add test coverage for reg_set_min_max handling
  bpf: Reduce stack consumption in check_stack_write_fixed_off
  bpf: Fix reg_set_min_max corruption of fake_reg
  MAINTAINERS: mailmap: Update Stanislav's email address
====================

Link: https://lore.kernel.org/r/20240614203223.26500-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-14 17:57:10 -07:00
GUO Zihua
9a95c5bfbf ima: Avoid blocking in RCU read-side critical section
A panic happens in ima_match_policy:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
PGD 42f873067 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 5 PID: 1286325 Comm: kubeletmonit.sh
Kdump: loaded Tainted: P
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
               BIOS 0.0.0 02/06/2015
RIP: 0010:ima_match_policy+0x84/0x450
Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39
      7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d
      f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea
      44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f
RSP: 0018:ff71570009e07a80 EFLAGS: 00010207
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200
RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739
R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970
R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001
FS:  00007f5195b51740(0000)
GS:ff3e278b12d40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ima_get_action+0x22/0x30
 process_measurement+0xb0/0x830
 ? page_add_file_rmap+0x15/0x170
 ? alloc_set_pte+0x269/0x4c0
 ? prep_new_page+0x81/0x140
 ? simple_xattr_get+0x75/0xa0
 ? selinux_file_open+0x9d/0xf0
 ima_file_check+0x64/0x90
 path_openat+0x571/0x1720
 do_filp_open+0x9b/0x110
 ? page_counter_try_charge+0x57/0xc0
 ? files_cgroup_alloc_fd+0x38/0x60
 ? __alloc_fd+0xd4/0x250
 ? do_sys_open+0x1bd/0x250
 do_sys_open+0x1bd/0x250
 do_syscall_64+0x5d/0x1d0
 entry_SYSCALL_64_after_hwframe+0x65/0xca

Commit c7423dbdbc ("ima: Handle -ESTALE returned by
ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a
RCU read-side critical section which contains kmalloc with GFP_KERNEL.
This implies a possible sleep and violates limitations of RCU read-side
critical sections on non-PREEMPT systems.

Sleeping within RCU read-side critical section might cause
synchronize_rcu() returning early and break RCU protection, allowing a
UAF to happen.

The root cause of this issue could be described as follows:
|	Thread A	|	Thread B	|
|			|ima_match_policy	|
|			|  rcu_read_lock	|
|ima_lsm_update_rule	|			|
|  synchronize_rcu	|			|
|			|    kmalloc(GFP_KERNEL)|
|			|      sleep		|
==> synchronize_rcu returns early
|  kfree(entry)		|			|
|			|    entry = entry->next|
==> UAF happens and entry now becomes NULL (or could be anything).
|			|    entry->action	|
==> Accessing entry might cause panic.

To fix this issue, we are converting all kmalloc that is called within
RCU read-side critical section to use GFP_ATOMIC.

Fixes: c7423dbdbc ("ima: Handle -ESTALE returned by ima_filter_rule_match()")
Cc: stable@vger.kernel.org
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-06-13 14:26:50 -04:00
Maciej Żenczykowski
b99a95bc56 bpf: fix UML x86_64 compile failure
pcpu_hot (defined in arch/x86) is not available on user mode linux (ARCH=um)

Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Fixes: 1ae6921009 ("bpf: inline bpf_get_smp_processor_id() helper")
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20240613173146.2524647-1-maze@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-13 11:24:45 -07:00
Daniel Borkmann
e73cd1cfc2 bpf: Reduce stack consumption in check_stack_write_fixed_off
The fake_reg moved into env->fake_reg given it consumes a lot of stack
space (120 bytes). Migrate the fake_reg in check_stack_write_fixed_off()
as well now that we have it.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20240613115310.25383-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-13 11:16:01 -07:00
Daniel Borkmann
9242480126 bpf: Fix reg_set_min_max corruption of fake_reg
Juan reported that after doing some changes to buzzer [0] and implementing
a new fuzzing strategy guided by coverage, they noticed the following in
one of the probes:

  [...]
  13: (79) r6 = *(u64 *)(r0 +0)         ; R0=map_value(ks=4,vs=8) R6_w=scalar()
  14: (b7) r0 = 0                       ; R0_w=0
  15: (b4) w0 = -1                      ; R0_w=0xffffffff
  16: (74) w0 >>= 1                     ; R0_w=0x7fffffff
  17: (5c) w6 &= w0                     ; R0_w=0x7fffffff R6_w=scalar(smin=smin32=0,smax=umax=umax32=0x7fffffff,var_off=(0x0; 0x7fffffff))
  18: (44) w6 |= 2                      ; R6_w=scalar(smin=umin=smin32=umin32=2,smax=umax=umax32=0x7fffffff,var_off=(0x2; 0x7ffffffd))
  19: (56) if w6 != 0x7ffffffd goto pc+1
  REG INVARIANTS VIOLATION (true_reg2): range bounds violation u64=[0x7fffffff, 0x7ffffffd] s64=[0x7fffffff, 0x7ffffffd] u32=[0x7fffffff, 0x7ffffffd] s32=[0x7fffffff, 0x7ffffffd] var_off=(0x7fffffff, 0x0)
  REG INVARIANTS VIOLATION (false_reg1): range bounds violation u64=[0x7fffffff, 0x7ffffffd] s64=[0x7fffffff, 0x7ffffffd] u32=[0x7fffffff, 0x7ffffffd] s32=[0x7fffffff, 0x7ffffffd] var_off=(0x7fffffff, 0x0)
  REG INVARIANTS VIOLATION (false_reg2): const tnum out of sync with range bounds u64=[0x0, 0xffffffffffffffff] s64=[0x8000000000000000, 0x7fffffffffffffff] u32=[0x0, 0xffffffff] s32=[0x80000000, 0x7fffffff] var_off=(0x7fffffff, 0x0)
  19: R6_w=0x7fffffff
  20: (95) exit

  from 19 to 21: R0=0x7fffffff R6=scalar(smin=umin=smin32=umin32=2,smax=umax=smax32=umax32=0x7ffffffe,var_off=(0x2; 0x7ffffffd)) R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm
  21: R0=0x7fffffff R6=scalar(smin=umin=smin32=umin32=2,smax=umax=smax32=umax32=0x7ffffffe,var_off=(0x2; 0x7ffffffd)) R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm
  21: (14) w6 -= 2147483632             ; R6_w=scalar(smin=umin=umin32=2,smax=umax=0xffffffff,smin32=0x80000012,smax32=14,var_off=(0x2; 0xfffffffd))
  22: (76) if w6 s>= 0xe goto pc+1      ; R6_w=scalar(smin=umin=umin32=2,smax=umax=0xffffffff,smin32=0x80000012,smax32=13,var_off=(0x2; 0xfffffffd))
  23: (95) exit

  from 22 to 24: R0=0x7fffffff R6_w=14 R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm
  24: R0=0x7fffffff R6_w=14 R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm
  24: (14) w6 -= 14                     ; R6_w=0
  [...]

What can be seen here is a register invariant violation on line 19. After
the binary-or in line 18, the verifier knows that bit 2 is set but knows
nothing about the rest of the content which was loaded from a map value,
meaning, range is [2,0x7fffffff] with var_off=(0x2; 0x7ffffffd). When in
line 19 the verifier analyzes the branch, it splits the register states
in reg_set_min_max() into the registers of the true branch (true_reg1,
true_reg2) and the registers of the false branch (false_reg1, false_reg2).

Since the test is w6 != 0x7ffffffd, the src_reg is a known constant.
Internally, the verifier creates a "fake" register initialized as scalar
to the value of 0x7ffffffd, and then passes it onto reg_set_min_max(). Now,
for line 19, it is mathematically impossible to take the false branch of
this program, yet the verifier analyzes it. It is impossible because the
second bit of r6 will be set due to the prior or operation and the
constant in the condition has that bit unset (hex(fd) == binary(1111 1101).

When the verifier first analyzes the false / fall-through branch, it will
compute an intersection between the var_off of r6 and of the constant. This
is because the verifier creates a "fake" register initialized to the value
of the constant. The intersection result later refines both registers in
regs_refine_cond_op():

  [...]
  t = tnum_intersect(tnum_subreg(reg1->var_off), tnum_subreg(reg2->var_off));
  reg1->var_off = tnum_with_subreg(reg1->var_off, t);
  reg2->var_off = tnum_with_subreg(reg2->var_off, t);
  [...]

Since the verifier is analyzing the false branch of the conditional jump,
reg1 is equal to false_reg1 and reg2 is equal to false_reg2, i.e. the reg2
is the "fake" register that was meant to hold a constant value. The resulting
var_off of the intersection says that both registers now hold a known value
of var_off=(0x7fffffff, 0x0) or in other words: this operation manages to
make the verifier think that the "constant" value that was passed in the
jump operation now holds a different value.

Normally this would not be an issue since it should not influence the true
branch, however, false_reg2 and true_reg2 are pointers to the same "fake"
register. Meaning, the false branch can influence the results of the true
branch. In line 24, the verifier assumes R6_w=0, but the actual runtime
value in this case is 1. The fix is simply not passing in the same "fake"
register location as inputs to reg_set_min_max(), but instead making a
copy. Moving the fake_reg into the env also reduces stack consumption by
120 bytes. With this, the verifier successfully rejects invalid accesses
from the test program.

  [0] https://github.com/google/buzzer

Fixes: 67420501e8 ("bpf: generalize reg_set_min_max() to handle non-const register comparisons")
Reported-by: Juan José López Jaimez <jjlopezjaimez@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20240613115310.25383-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-13 11:16:01 -07:00
Masami Hiramatsu (Google)
3572bd5689 tracing: Build event generation tests only as modules
The kprobes and synth event generation test modules add events and lock
(get a reference) those event file reference in module init function,
and unlock and delete it in module exit function. This is because those
are designed for playing as modules.

If we make those modules as built-in, those events are left locked in the
kernel, and never be removed. This causes kprobe event self-test failure
as below.

[   97.349708] ------------[ cut here ]------------
[   97.353453] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:2133 kprobe_trace_self_tests_init+0x3f1/0x480
[   97.357106] Modules linked in:
[   97.358488] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.9.0-g699646734ab5-dirty #14
[   97.361556] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[   97.363880] RIP: 0010:kprobe_trace_self_tests_init+0x3f1/0x480
[   97.365538] Code: a8 24 08 82 e9 ae fd ff ff 90 0f 0b 90 48 c7 c7 e5 aa 0b 82 e9 ee fc ff ff 90 0f 0b 90 48 c7 c7 2d 61 06 82 e9 8e fd ff ff 90 <0f> 0b 90 48 c7 c7 33 0b 0c 82 89 c6 e8 6e 03 1f ff 41 ff c7 e9 90
[   97.370429] RSP: 0000:ffffc90000013b50 EFLAGS: 00010286
[   97.371852] RAX: 00000000fffffff0 RBX: ffff888005919c00 RCX: 0000000000000000
[   97.373829] RDX: ffff888003f40000 RSI: ffffffff8236a598 RDI: ffff888003f40a68
[   97.375715] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
[   97.377675] R10: ffffffff811c9ae5 R11: ffffffff8120c4e0 R12: 0000000000000000
[   97.379591] R13: 0000000000000001 R14: 0000000000000015 R15: 0000000000000000
[   97.381536] FS:  0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000
[   97.383813] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   97.385449] CR2: 0000000000000000 CR3: 0000000002244000 CR4: 00000000000006b0
[   97.387347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   97.389277] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   97.391196] Call Trace:
[   97.391967]  <TASK>
[   97.392647]  ? __warn+0xcc/0x180
[   97.393640]  ? kprobe_trace_self_tests_init+0x3f1/0x480
[   97.395181]  ? report_bug+0xbd/0x150
[   97.396234]  ? handle_bug+0x3e/0x60
[   97.397311]  ? exc_invalid_op+0x1a/0x50
[   97.398434]  ? asm_exc_invalid_op+0x1a/0x20
[   97.399652]  ? trace_kprobe_is_busy+0x20/0x20
[   97.400904]  ? tracing_reset_all_online_cpus+0x15/0x90
[   97.402304]  ? kprobe_trace_self_tests_init+0x3f1/0x480
[   97.403773]  ? init_kprobe_trace+0x50/0x50
[   97.404972]  do_one_initcall+0x112/0x240
[   97.406113]  do_initcall_level+0x95/0xb0
[   97.407286]  ? kernel_init+0x1a/0x1a0
[   97.408401]  do_initcalls+0x3f/0x70
[   97.409452]  kernel_init_freeable+0x16f/0x1e0
[   97.410662]  ? rest_init+0x1f0/0x1f0
[   97.411738]  kernel_init+0x1a/0x1a0
[   97.412788]  ret_from_fork+0x39/0x50
[   97.413817]  ? rest_init+0x1f0/0x1f0
[   97.414844]  ret_from_fork_asm+0x11/0x20
[   97.416285]  </TASK>
[   97.417134] irq event stamp: 13437323
[   97.418376] hardirqs last  enabled at (13437337): [<ffffffff8110bc0c>] console_unlock+0x11c/0x150
[   97.421285] hardirqs last disabled at (13437370): [<ffffffff8110bbf1>] console_unlock+0x101/0x150
[   97.423838] softirqs last  enabled at (13437366): [<ffffffff8108e17f>] handle_softirqs+0x23f/0x2a0
[   97.426450] softirqs last disabled at (13437393): [<ffffffff8108e346>] __irq_exit_rcu+0x66/0xd0
[   97.428850] ---[ end trace 0000000000000000 ]---

And also, since we can not cleanup dynamic_event file, ftracetest are
failed too.

To avoid these issues, build these tests only as modules.

Link: https://lore.kernel.org/all/171811263754.85078.5877446624311852525.stgit@devnote2/

Fixes: 9fe41efaca ("tracing: Add synth event generation test module")
Fixes: 64836248dd ("tracing: Add kprobe event command generation test module")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-12 08:43:12 +09:00
Oleg Nesterov
07c54cc598 tick/nohz_full: Don't abuse smp_call_function_single() in tick_setup_device()
After the recent commit 5097cbcb38 ("sched/isolation: Prevent boot crash
when the boot CPU is nohz_full") the kernel no longer crashes, but there is
another problem.

In this case tick_setup_device() calls tick_take_do_timer_from_boot() to
update tick_do_timer_cpu and this triggers the WARN_ON_ONCE(irqs_disabled)
in smp_call_function_single().

Kill tick_take_do_timer_from_boot() and just use WRITE_ONCE(), the new
comment explains why this is safe (thanks Thomas!).

Fixes: 08ae95f4fd ("nohz_full: Allow the boot CPU to be nohz_full")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240528122019.GA28794@redhat.com
Link: https://lore.kernel.org/all/20240522151742.GA10400@redhat.com
2024-06-10 20:18:13 +02:00
Linus Torvalds
7cec2e16cb Fix race between perf_event_free_task() and perf_event_release_kernel()
that can result in missed wakeups and hung tasks.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-urgent-2024-06-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf event fix from Ingo Molnar:
 "Fix race between perf_event_free_task() and perf_event_release_kernel()
  that can result in missed wakeups and hung tasks"

* tag 'perf-urgent-2024-06-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix missing wakeup when waiting for context reference
2024-06-08 09:26:59 -07:00
Linus Torvalds
d30d0e49da Including fixes from BPF and big collection of fixes for WiFi core
and drivers.
 
 Current release - regressions:
 
  - vxlan: fix regression when dropping packets due to invalid src addresses
 
  - bpf: fix a potential use-after-free in bpf_link_free()
 
  - xdp: revert support for redirect to any xsk socket bound to the same
    UMEM as it can result in a corruption
 
  - virtio_net:
    - add missing lock protection when reading return code from control_buf
    - fix false-positive lockdep splat in DIM
    - Revert "wifi: wilc1000: convert list management to RCU"
 
  - wifi: ath11k: fix error path in ath11k_pcic_ext_irq_config
 
 Previous releases - regressions:
 
  - rtnetlink: make the "split" NLM_DONE handling generic, restore the old
    behavior for two cases where we started coalescing those messages with
    normal messages, breaking sloppily-coded userspace
 
  - wifi:
    - cfg80211: validate HE operation element parsing
    - cfg80211: fix 6 GHz scan request building
    - mt76: mt7615: add missing chanctx ops
    - ath11k: move power type check to ASSOC stage, fix connecting
      to 6 GHz AP
    - ath11k: fix WCN6750 firmware crash caused by 17 num_vdevs
    - rtlwifi: ignore IEEE80211_CONF_CHANGE_RETRY_LIMITS
    - iwlwifi: mvm: fix a crash on 7265
 
 Previous releases - always broken:
 
  - ncsi: prevent multi-threaded channel probing, a spec violation
 
  - vmxnet3: disable rx data ring on dma allocation failure
 
  - ethtool: init tsinfo stats if requested, prevent unintentionally
    reporting all-zero stats on devices which don't implement any
 
  - dst_cache: fix possible races in less common IPv6 features
 
  - tcp: auth: don't consider TCP_CLOSE to be in TCP_AO_ESTABLISHED
 
  - ax25: fix two refcounting bugs
 
  - eth: ionic: fix kernel panic in XDP_TX action
 
 Misc:
 
  - tcp: count CLOSE-WAIT sockets for TCP_MIB_CURRESTAB
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-6.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from BPF and big collection of fixes for WiFi core and
  drivers.

  Current release - regressions:

   - vxlan: fix regression when dropping packets due to invalid src
     addresses

   - bpf: fix a potential use-after-free in bpf_link_free()

   - xdp: revert support for redirect to any xsk socket bound to the
     same UMEM as it can result in a corruption

   - virtio_net:
      - add missing lock protection when reading return code from
        control_buf
      - fix false-positive lockdep splat in DIM
      - Revert "wifi: wilc1000: convert list management to RCU"

   - wifi: ath11k: fix error path in ath11k_pcic_ext_irq_config

  Previous releases - regressions:

   - rtnetlink: make the "split" NLM_DONE handling generic, restore the
     old behavior for two cases where we started coalescing those
     messages with normal messages, breaking sloppily-coded userspace

   - wifi:
      - cfg80211: validate HE operation element parsing
      - cfg80211: fix 6 GHz scan request building
      - mt76: mt7615: add missing chanctx ops
      - ath11k: move power type check to ASSOC stage, fix connecting to
        6 GHz AP
      - ath11k: fix WCN6750 firmware crash caused by 17 num_vdevs
      - rtlwifi: ignore IEEE80211_CONF_CHANGE_RETRY_LIMITS
      - iwlwifi: mvm: fix a crash on 7265

  Previous releases - always broken:

   - ncsi: prevent multi-threaded channel probing, a spec violation

   - vmxnet3: disable rx data ring on dma allocation failure

   - ethtool: init tsinfo stats if requested, prevent unintentionally
     reporting all-zero stats on devices which don't implement any

   - dst_cache: fix possible races in less common IPv6 features

   - tcp: auth: don't consider TCP_CLOSE to be in TCP_AO_ESTABLISHED

   - ax25: fix two refcounting bugs

   - eth: ionic: fix kernel panic in XDP_TX action

  Misc:

   - tcp: count CLOSE-WAIT sockets for TCP_MIB_CURRESTAB"

* tag 'net-6.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (107 commits)
  selftests: net: lib: set 'i' as local
  selftests: net: lib: avoid error removing empty netns name
  selftests: net: lib: support errexit with busywait
  net: ethtool: fix the error condition in ethtool_get_phy_stats_ethtool()
  ipv6: fix possible race in __fib6_drop_pcpu_from()
  af_unix: Annotate data-race of sk->sk_shutdown in sk_diag_fill().
  af_unix: Use skb_queue_len_lockless() in sk_diag_show_rqlen().
  af_unix: Use skb_queue_empty_lockless() in unix_release_sock().
  af_unix: Use unix_recvq_full_lockless() in unix_stream_connect().
  af_unix: Annotate data-race of net->unx.sysctl_max_dgram_qlen.
  af_unix: Annotate data-races around sk->sk_sndbuf.
  af_unix: Annotate data-races around sk->sk_state in UNIX_DIAG.
  af_unix: Annotate data-race of sk->sk_state in unix_stream_read_skb().
  af_unix: Annotate data-races around sk->sk_state in sendmsg() and recvmsg().
  af_unix: Annotate data-race of sk->sk_state in unix_accept().
  af_unix: Annotate data-race of sk->sk_state in unix_stream_connect().
  af_unix: Annotate data-races around sk->sk_state in unix_write_space() and poll().
  af_unix: Annotate data-race of sk->sk_state in unix_inq_len().
  af_unix: Annodate data-races around sk->sk_state for writers.
  af_unix: Set sk->sk_state under unix_state_lock() for truly disconencted peer.
  ...
2024-06-06 09:55:27 -07:00
Haifeng Xu
74751ef5c1 perf/core: Fix missing wakeup when waiting for context reference
In our production environment, we found many hung tasks which are
blocked for more than 18 hours. Their call traces are like this:

[346278.191038] __schedule+0x2d8/0x890
[346278.191046] schedule+0x4e/0xb0
[346278.191049] perf_event_free_task+0x220/0x270
[346278.191056] ? init_wait_var_entry+0x50/0x50
[346278.191060] copy_process+0x663/0x18d0
[346278.191068] kernel_clone+0x9d/0x3d0
[346278.191072] __do_sys_clone+0x5d/0x80
[346278.191076] __x64_sys_clone+0x25/0x30
[346278.191079] do_syscall_64+0x5c/0xc0
[346278.191083] ? syscall_exit_to_user_mode+0x27/0x50
[346278.191086] ? do_syscall_64+0x69/0xc0
[346278.191088] ? irqentry_exit_to_user_mode+0x9/0x20
[346278.191092] ? irqentry_exit+0x19/0x30
[346278.191095] ? exc_page_fault+0x89/0x160
[346278.191097] ? asm_exc_page_fault+0x8/0x30
[346278.191102] entry_SYSCALL_64_after_hwframe+0x44/0xae

The task was waiting for the refcount become to 1, but from the vmcore,
we found the refcount has already been 1. It seems that the task didn't
get woken up by perf_event_release_kernel() and got stuck forever. The
below scenario may cause the problem.

Thread A					Thread B
...						...
perf_event_free_task				perf_event_release_kernel
						   ...
						   acquire event->child_mutex
						   ...
						   get_ctx
   ...						   release event->child_mutex
   acquire ctx->mutex
   ...
   perf_free_event (acquire/release event->child_mutex)
   ...
   release ctx->mutex
   wait_var_event
						   acquire ctx->mutex
						   acquire event->child_mutex
						   # move existing events to free_list
						   release event->child_mutex
						   release ctx->mutex
						   put_ctx
...						...

In this case, all events of the ctx have been freed, so we couldn't
find the ctx in free_list and Thread A will miss the wakeup. It's thus
necessary to add a wakeup after dropping the reference.

Fixes: 1cf8dfe8a6 ("perf/core: Fix race between close() and fork()")
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20240513103948.33570-1-haifeng.xu@shopee.com
2024-06-05 15:52:33 +02:00
Cong Wang
2884dc7d08 bpf: Fix a potential use-after-free in bpf_link_free()
After commit 1a80dbcb2d, bpf_link can be freed by
link->ops->dealloc_deferred, but the code still tests and uses
link->ops->dealloc afterward, which leads to a use-after-free as
reported by syzbot. Actually, one of them should be sufficient, so
just call one of them instead of both. Also add a WARN_ON() in case
of any problematic implementation.

Fixes: 1a80dbcb2d ("bpf: support deferring bpf_link dealloc to after RCU grace period")
Reported-by: syzbot+1989ee16d94720836244@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240602182703.207276-1-xiyou.wangcong@gmail.com
2024-06-03 18:16:19 +02:00