Commit Graph

24283 Commits

Author SHA1 Message Date
Dave Airlie
856ee92e86 Linux 4.11-rc7
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Merge tag 'v4.11-rc7' into drm-next

Backmerge Linux 4.11-rc7 from Linus tree, to fix some
conflicts that were causing problems with the rerere cache
in drm-tip.
2017-04-19 11:07:14 +10:00
Linus Torvalds
11c994d9a5 Merge branch 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
 "Unfortunately, the commit to fix the cgroup mount race in the previous
  pull request can lead to hangs.

  The original bug has been around for a while and isn't too likely to
  be triggered in usual use cases. Revert the commit for now"

* 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Revert "cgroup: avoid attaching a cgroup root to two different superblocks"
2017-04-16 11:48:10 -07:00
Linus Torvalds
48538861b9 While rewriting the function probe code, I stumbled over a long standing
bug. This bug has been there sinc function tracing was added way back
 when. But my new development depends on this bug being fixed, and it
 should be fixed regardless as it causes ftrace to disable itself when
 triggered, and a reboot is required to enable it again.
 
 The bug is that the function probe does not disable itself properly
 if there's another probe of its type still enabled. For example:
 
      # cd /sys/kernel/debug/tracing
      # echo schedule:traceoff > set_ftrace_filter
      # echo do_IRQ:traceoff > set_ftrace_filter
      # echo \!do_IRQ:traceoff > /debug/tracing/set_ftrace_filter
      # echo do_IRQ:traceoff > set_ftrace_filter
 
 The above registers two traceoff probes (one for schedule and one for
 do_IRQ, and then removes do_IRQ. But since there still exists one for
 schedule, it is not done properly. When adding do_IRQ back, the breakage
 in the accounting is noticed by the ftrace self tests, and it causes
 a warning and disables ftrace.
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Merge tag 'trace-v4.11-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull ftrace fix from Steven Rostedt:
 "While rewriting the function probe code, I stumbled over a long
  standing bug. This bug has been there sinc function tracing was added
  way back when. But my new development depends on this bug being fixed,
  and it should be fixed regardless as it causes ftrace to disable
  itself when triggered, and a reboot is required to enable it again.

  The bug is that the function probe does not disable itself properly if
  there's another probe of its type still enabled. For example:

     # cd /sys/kernel/debug/tracing
     # echo schedule:traceoff > set_ftrace_filter
     # echo do_IRQ:traceoff > set_ftrace_filter
     # echo \!do_IRQ:traceoff > /debug/tracing/set_ftrace_filter
     # echo do_IRQ:traceoff > set_ftrace_filter

  The above registers two traceoff probes (one for schedule and one for
  do_IRQ, and then removes do_IRQ.

  But since there still exists one for schedule, it is not done
  properly. When adding do_IRQ back, the breakage in the accounting is
  noticed by the ftrace self tests, and it causes a warning and disables
  ftrace"

* tag 'trace-v4.11-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix removing of second function probe
2017-04-16 10:01:34 -07:00
Tejun Heo
330c418638 Revert "cgroup: avoid attaching a cgroup root to two different superblocks"
This reverts commit bfb0b80db5.

Andrei reports CRIU test hangs with the patch applied.  The bug fixed
by the patch isn't too likely to trigger in actual uses.  Revert the
patch for now.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Andrei Vagin <avagin@virtuozzo.com>
Link: http://lkml.kernel.org/r/20170414232737.GC20350@outlook.office365.com
2017-04-16 23:17:37 +09:00
Linus Torvalds
7e703eccf0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "Things seem to be settling down as far as networking is concerned,
  let's hope this trend continues...

   1) Add iov_iter_revert() and use it to fix the behavior of
      skb_copy_datagram_msg() et al., from Al Viro.

   2) Fix the protocol used in the synthetic SKB we cons up for the
      purposes of doing a simulated route lookup for RTM_GETROUTE
      requests. From Florian Larysch.

   3) Don't add noop_qdisc to the per-device qdisc hashes, from Cong
      Wang.

   4) Don't call netdev_change_features with the team lock held, from
      Xin Long.

   5) Revert TCP F-RTO extension to catch more spurious timeouts because
      it interacts very badly with some middle-boxes. From Yuchung
      Cheng.

   6) Fix the loss of error values in l2tp {s,g}etsockopt calls, from
      Guillaume Nault.

   7) ctnetlink uses bit positions where it should be using bit masks,
      fix from Liping Zhang.

   8) Missing RCU locking in netfilter helper code, from Gao Feng.

   9) Avoid double frees and use-after-frees in tcp_disconnect(), from
      Eric Dumazet.

  10) Don't do a changelink before we register the netdevice in
      bridging, from Ido Schimmel.

  11) Lock the ipv6 device address list properly, from Rabin Vincent"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (29 commits)
  netfilter: ipt_CLUSTERIP: Fix wrong conntrack netns refcnt usage
  netfilter: nft_hash: do not dump the auto generated seed
  drivers: net: usb: qmi_wwan: add QMI_QUIRK_SET_DTR for Telit PID 0x1201
  ipv6: Fix idev->addr_list corruption
  net: xdp: don't export dev_change_xdp_fd()
  bridge: netlink: register netdevice before executing changelink
  bridge: implement missing ndo_uninit()
  bpf: reference may_access_skb() from __bpf_prog_run()
  tcp: clear saved_syn in tcp_disconnect()
  netfilter: nf_ct_expect: use proper RCU list traversal/update APIs
  netfilter: ctnetlink: skip dumping expect when nfct_help(ct) is NULL
  netfilter: make it safer during the inet6_dev->addr_list traversal
  netfilter: ctnetlink: make it safer when checking the ct helper name
  netfilter: helper: Add the rcu lock when call __nf_conntrack_helper_find
  netfilter: ctnetlink: using bit to represent the ct event
  netfilter: xt_TCPMSS: add more sanity tests on tcph->doff
  net: tcp: Increase TCP_MIB_OUTRSTS even though fail to alloc skb
  l2tp: don't mask errors in pppol2tp_getsockopt()
  l2tp: don't mask errors in pppol2tp_setsockopt()
  tcp: restrict F-RTO to work-around broken middle-boxes
  ...
2017-04-14 17:38:24 -07:00
Linus Torvalds
d295917a47 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
 "The irq department provides:

   - two fixes for the CPU affinity spread infrastructure to prevent
     unbalanced spreading in corner cases which leads to horrible
     performance, because interrupts are rather aggregated than spread

   - add a missing spinlock initializer in the imx-gpcv2 init code"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/irq-imx-gpcv2: Fix spinlock initialization
  irq/affinity: Fix extra vecs calculation
  irq/affinity: Fix CPU spread for unbalanced nodes
2017-04-14 16:57:14 -07:00
Steven Rostedt (VMware)
82cc4fc2e7 ftrace: Fix removing of second function probe
When two function probes are added to set_ftrace_filter, and then one of
them is removed, the update to the function locations is not performed, and
the record keeping of the function states are corrupted, and causes an
ftrace_bug() to occur.

This is easily reproducable by adding two probes, removing one, and then
adding it back again.

 # cd /sys/kernel/debug/tracing
 # echo schedule:traceoff > set_ftrace_filter
 # echo do_IRQ:traceoff > set_ftrace_filter
 # echo \!do_IRQ:traceoff > /debug/tracing/set_ftrace_filter
 # echo do_IRQ:traceoff > set_ftrace_filter

Causes:
 ------------[ cut here ]------------
 WARNING: CPU: 2 PID: 1098 at kernel/trace/ftrace.c:2369 ftrace_get_addr_curr+0x143/0x220
 Modules linked in: [...]
 CPU: 2 PID: 1098 Comm: bash Not tainted 4.10.0-test+ #405
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
 Call Trace:
  dump_stack+0x68/0x9f
  __warn+0x111/0x130
  ? trace_irq_work_interrupt+0xa0/0xa0
  warn_slowpath_null+0x1d/0x20
  ftrace_get_addr_curr+0x143/0x220
  ? __fentry__+0x10/0x10
  ftrace_replace_code+0xe3/0x4f0
  ? ftrace_int3_handler+0x90/0x90
  ? printk+0x99/0xb5
  ? 0xffffffff81000000
  ftrace_modify_all_code+0x97/0x110
  arch_ftrace_update_code+0x10/0x20
  ftrace_run_update_code+0x1c/0x60
  ftrace_run_modify_code.isra.48.constprop.62+0x8e/0xd0
  register_ftrace_function_probe+0x4b6/0x590
  ? ftrace_startup+0x310/0x310
  ? debug_lockdep_rcu_enabled.part.4+0x1a/0x30
  ? update_stack_state+0x88/0x110
  ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320
  ? preempt_count_sub+0x18/0xd0
  ? mutex_lock_nested+0x104/0x800
  ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320
  ? __unwind_start+0x1c0/0x1c0
  ? _mutex_lock_nest_lock+0x800/0x800
  ftrace_trace_probe_callback.isra.3+0xc0/0x130
  ? func_set_flag+0xe0/0xe0
  ? __lock_acquire+0x642/0x1790
  ? __might_fault+0x1e/0x20
  ? trace_get_user+0x398/0x470
  ? strcmp+0x35/0x60
  ftrace_trace_onoff_callback+0x48/0x70
  ftrace_regex_write.isra.43.part.44+0x251/0x320
  ? match_records+0x420/0x420
  ftrace_filter_write+0x2b/0x30
  __vfs_write+0xd7/0x330
  ? do_loop_readv_writev+0x120/0x120
  ? locks_remove_posix+0x90/0x2f0
  ? do_lock_file_wait+0x160/0x160
  ? __lock_is_held+0x93/0x100
  ? rcu_read_lock_sched_held+0x5c/0xb0
  ? preempt_count_sub+0x18/0xd0
  ? __sb_start_write+0x10a/0x230
  ? vfs_write+0x222/0x240
  vfs_write+0xef/0x240
  SyS_write+0xab/0x130
  ? SyS_read+0x130/0x130
  ? trace_hardirqs_on_caller+0x182/0x280
  ? trace_hardirqs_on_thunk+0x1a/0x1c
  entry_SYSCALL_64_fastpath+0x18/0xad
 RIP: 0033:0x7fe61c157c30
 RSP: 002b:00007ffe87890258 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: ffffffff8114a410 RCX: 00007fe61c157c30
 RDX: 0000000000000010 RSI: 000055814798f5e0 RDI: 0000000000000001
 RBP: ffff8800c9027f98 R08: 00007fe61c422740 R09: 00007fe61ca53700
 R10: 0000000000000073 R11: 0000000000000246 R12: 0000558147a36400
 R13: 00007ffe8788f160 R14: 0000000000000024 R15: 00007ffe8788f15c
  ? trace_hardirqs_off_caller+0xc0/0x110
 ---[ end trace 99fa09b3d9869c2c ]---
 Bad trampoline accounting at: ffffffff81cc3b00 (do_IRQ+0x0/0x150)

Cc: stable@vger.kernel.org
Fixes: 59df055f19 ("ftrace: trace different functions with a different tracer")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-14 17:54:22 -04:00
Keith Busch
3412386b53 irq/affinity: Fix extra vecs calculation
This fixes a math error calculating the extra_vecs. The error assumed
only 1 cpu per vector, but the value needs to account for the actual
number of cpus per vector in order to get the correct remainder for
extra CPU assignment.

Fixes: 7bf8222b9b ("irq/affinity: Fix CPU spread for unbalanced nodes")
Reported-by: Xiaolong Ye <xiaolong.ye@intel.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Link: http://lkml.kernel.org/r/1492104492-19943-1-git-send-email-keith.busch@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-04-13 23:41:00 +02:00
Linus Torvalds
b9b3322f13 Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit
Pull audit fix from Paul Moore:
 "One more small audit fix, this should be the last for v4.11.

  Seth Forshee noticed a problem where the audit retry queue wasn't
  being flushed properly when audit was enabled and the audit daemon
  wasn't running; this patches fixes the problem (see the commit
  description for more details on the change).

  Both Seth and I have tested this and everything looks good"

* 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit:
  audit: make sure we don't let the retry queue grow without bounds
2017-04-12 00:02:33 -07:00
Linus Torvalds
06ea4c38bc Merge branch 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
 "This contains fixes for two long standing subtle bugs:

   - kthread_bind() on a new kthread binds it to specific CPUs and
     prevents userland from messing with the affinity or cgroup
     membership. Unfortunately, for cgroup membership, there's a window
     between kthread creation and kthread_bind*() invocation where the
     kthread can be moved into a non-root cgroup by userland.

     Depending on what controllers are in effect, this can assign the
     kthread unexpected attributes. For example, in the reported case,
     workqueue workers ended up in a non-root cpuset cgroups and had
     their CPU affinities overridden. This broke workqueue invariants
     and led to workqueue stalls.

     Fixed by closing the window between kthread creation and
     kthread_bind() as suggested by Oleg.

   - There was a bug in cgroup mount path which could allow two
     competing mount attempts to attach the same cgroup_root to two
     different superblocks.

     This was caused by mishandling return value from kernfs_pin_sb().

     Fixed"

* 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: avoid attaching a cgroup root to two different superblocks
  cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups
2017-04-11 23:38:16 -07:00
Johannes Berg
96a94cc515 bpf: reference may_access_skb() from __bpf_prog_run()
It took me quite some time to figure out how this was linked,
so in order to save the next person the effort of finding it
add a comment in __bpf_prog_run() that indicates what exactly
determines that a program can access the ctx == skb.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-11 10:54:27 -04:00
Zefan Li
bfb0b80db5 cgroup: avoid attaching a cgroup root to two different superblocks
Run this:

    touch file0
    for ((; ;))
    {
        mount -t cpuset xxx file0
    }

And this concurrently:

    touch file1
    for ((; ;))
    {
        mount -t cpuset xxx file1
    }

We'll trigger a warning like this:

 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 4675 at lib/percpu-refcount.c:317 percpu_ref_kill_and_confirm+0x92/0xb0
 percpu_ref_kill_and_confirm called more than once on css_release!
 CPU: 1 PID: 4675 Comm: mount Not tainted 4.11.0-rc5+ #5
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
 Call Trace:
  dump_stack+0x63/0x84
  __warn+0xd1/0xf0
  warn_slowpath_fmt+0x5f/0x80
  percpu_ref_kill_and_confirm+0x92/0xb0
  cgroup_kill_sb+0x95/0xb0
  deactivate_locked_super+0x43/0x70
  deactivate_super+0x46/0x60
 ...
 ---[ end trace a79f61c2a2633700 ]---

Here's a race:

  Thread A				Thread B

  cgroup1_mount()
    # alloc a new cgroup root
    cgroup_setup_root()
					cgroup1_mount()
					  # no sb yet, returns NULL
					  kernfs_pin_sb()

					  # but succeeds in getting the refcnt,
					  # so re-use cgroup root
					  percpu_ref_tryget_live()
    # alloc sb with cgroup root
    cgroup_do_mount()

  cgroup_kill_sb()
					  # alloc another sb with same root
					  cgroup_do_mount()

					cgroup_kill_sb()

We end up using the same cgroup root for two different superblocks,
so percpu_ref_kill() will be called twice on the same root when the
two superblocks are destroyed.

We should fix to make sure the superblock pinning is really successful.

Cc: stable@vger.kernel.org # 3.16+
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2017-04-11 09:00:57 +09:00
Dave Airlie
b769fefb68 Linux 4.11-rc6
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Backmerge tag 'v4.11-rc6' into drm-next

Linux 4.11-rc6

drm-misc needs 4.11-rc5, may as well fix conflicts with rc6.
2017-04-11 07:40:42 +10:00
Paul Moore
264d509637 audit: make sure we don't let the retry queue grow without bounds
The retry queue is intended to provide a temporary buffer in the case
of transient errors when communicating with auditd, it is not meant
as a long life queue, that functionality is provided by the hold
queue.

This patch fixes a problem identified by Seth where the retry queue
could grow uncontrollably if an auditd instance did not connect to
the kernel to drain the queues.  This commit fixes this by doing the
following:

* Make sure we always call auditd_reset() if we decide the connection
with audit is really dead.  There were some cases in
kauditd_hold_skb() where we did not reset the connection, this patch
relocates the reset calls to kauditd_thread() so all the error
conditions are caught and the connection reset.  As a side effect,
this means we could move auditd_reset() and get rid of the forward
definition at the top of kernel/audit.c.

* We never checked the status of the auditd connection when
processing the main audit queue which meant that the retry queue
could grow unchecked.  This patch adds a call to auditd_reset()
after the main queue has been processed if auditd is not connected,
the auditd_reset() call will make sure the retry and hold queues are
correctly managed/flushed so that the retry queue remains reasonable.

Cc: <stable@vger.kernel.org> # 4.10.x-: 5b52330bbf
Reported-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-04-10 11:16:59 -04:00
Liping Zhang
425fffd886 sysctl: report EINVAL if value is larger than UINT_MAX for proc_douintvec
Currently, inputting the following command will succeed but actually the
value will be truncated:

  # echo 0x12ffffffff > /proc/sys/net/ipv4/tcp_notsent_lowat

This is not friendly to the user, so instead, we should report error
when the value is larger than UINT_MAX.

Fixes: e7d316a02f ("sysctl: handle error writing UINT_MAX to u32 fields")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-08 10:27:40 -07:00
Linus Torvalds
62fedca5ce Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit
Pull audit cleanup from Paul Moore:
 "A week later than I had hoped, but as promised, here is the audit
  uninline-fix we talked about during the last audit pull request.

  The patch is slightly different than what we originally discussed as
  it made more sense to keep the audit_signal_info() function in
  auditsc.c rather than move it and bunch of other related
  variables/definitions into audit.c/audit.h.

  At some point in the future I need to look at how the audit code is
  organized across kernel/audit*, I suspect we could do things a bit
  better, but it doesn't seem like a -rc release is a good place for
  that ;)

  Regardless, this patch passes our tests without problem and looks good
  for v4.11"

* 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit:
  audit: move audit_signal_info() into kernel/auditsc.c
2017-04-08 01:37:25 -07:00
bsegall@google.com
5402e97af6 ptrace: fix PTRACE_LISTEN race corrupting task->state
In PT_SEIZED + LISTEN mode STOP/CONT signals cause a wakeup against
__TASK_TRACED.  If this races with the ptrace_unfreeze_traced at the end
of a PTRACE_LISTEN, this can wake the task /after/ the check against
__TASK_TRACED, but before the reset of state to TASK_TRACED.  This
causes it to instead clobber TASK_WAKING, allowing a subsequent wakeup
against TRACED while the task is still on the rq wake_list, corrupting
it.

Oleg said:
 "The kernel can crash or this can lead to other hard-to-debug problems.
  In short, "task->state = TASK_TRACED" in ptrace_unfreeze_traced()
  assumes that nobody else can wake it up, but PTRACE_LISTEN breaks the
  contract. Obviusly it is very wrong to manipulate task->state if this
  task is already running, or WAKING, or it sleeps again"

[akpm@linux-foundation.org: coding-style fixes]
Fixes: 9899d11f ("ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILL")
Link: http://lkml.kernel.org/r/xm26y3vfhmkp.fsf_-_@bsegall-linux.mtv.corp.google.com
Signed-off-by: Ben Segall <bsegall@google.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-08 00:47:48 -07:00
Liping Zhang
5380e5644a sysctl: don't print negative flag for proc_douintvec
I saw some very confusing sysctl output on my system:
  # cat /proc/sys/net/core/xfrm_aevent_rseqth
  -2
  # cat /proc/sys/net/core/xfrm_aevent_etime
  -10
  # cat /proc/sys/net/ipv4/tcp_notsent_lowat
  -4294967295

Because we forget to set the *negp flag in proc_douintvec, so it will
become a garbage value.

Since the value related to proc_douintvec is always an unsigned integer,
so we can set *negp to false explictily to fix this issue.

Fixes: e7d316a02f ("sysctl: handle error writing UINT_MAX to u32 fields")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-07 09:46:44 -07:00
Linus Torvalds
4691f4a6d4 Wei Yongjun fixed a long standing bug in the ring buffer startup test.
If for some unknown reason, the kthread that is created fails to be
 created, the return from kthread_create() is an PTR_ERR and not a NULL.
 The test incorrectly checks for NULL instead of an error.
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Merge tag 'trace-v4.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Wei Yongjun fixed a long standing bug in the ring buffer startup test.

  If for some unknown reason, the kthread that is created fails to be
  created, the return from kthread_create() is an PTR_ERR and not a
  NULL. The test incorrectly checks for NULL instead of an error"

* tag 'trace-v4.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Fix return value check in test_ringbuffer()
2017-04-06 13:12:12 -07:00
Linus Torvalds
ea6b1720ce Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Reject invalid updates to netfilter expectation policies, from Pablo
    Neira Ayuso.

 2) Fix memory leak in nfnl_cthelper, from Jeffy Chen.

 3) Don't do stupid things if we get a neigh_probe() on a neigh entry
    whose ops lack a solicit method. From Eric Dumazet.

 4) Don't transmit packets in r8152 driver when the carrier is off, from
    Hayes Wang.

 5) Fix ipv6 packet type detection in aquantia driver, from Pavel
    Belous.

 6) Don't write uninitialized data into hw registers in bna driver, from
    Arnd Bergmann.

 7) Fix locking in ping_unhash(), from Eric Dumazet.

 8) Make BPF verifier range checks able to understand certain sequences
    emitted by LLVM, from Alexei Starovoitov.

 9) Fix use after free in ipconfig, from Mark Rutland.

10) Fix refcount leak on force commit in openvswitch, from Jarno
    Rajahalme.

11) Fix various overflow checks in AF_PACKET, from Andrey Konovalov.

12) Fix endianness bug in be2net driver, from Suresh Reddy.

13) Don't forget to wake TX queues when processing a timeout, from
    Grygorii Strashko.

14) ARP header on-stack storage is wrong in flow dissector, from Simon
    Horman.

15) Lost retransmit and reordering SNMP stats in TCP can be
    underreported. From Yuchung Cheng.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (82 commits)
  nfp: fix potential use after free on xdp prog
  tcp: fix reordering SNMP under-counting
  tcp: fix lost retransmit SNMP under-counting
  sctp: get sock from transport in sctp_transport_update_pmtu
  net: ethernet: ti: cpsw: fix race condition during open()
  l2tp: fix PPP pseudo-wire auto-loading
  bnx2x: fix spelling mistake in macros HW_INTERRUT_ASSERT_SET_*
  l2tp: take reference on sessions being dumped
  tcp: minimize false-positives on TCP/GRO check
  sctp: check for dst and pathmtu update in sctp_packet_config
  flow dissector: correct size of storage for ARP
  net: ethernet: ti: cpsw: wake tx queues on ndo_tx_timeout
  l2tp: take a reference on sessions used in genetlink handlers
  l2tp: hold session while sending creation notifications
  l2tp: fix duplicate session creation
  l2tp: ensure session can't get removed during pppol2tp_session_ioctl()
  l2tp: fix race in l2tp_recv_common()
  sctp: use right in and out stream cnt
  bpf: add various verifier test cases for self-tests
  bpf, verifier: fix rejection of unaligned access checks for map_value_adj
  ...
2017-04-05 20:17:38 -07:00
Wei Yongjun
62277de758 ring-buffer: Fix return value check in test_ringbuffer()
In case of error, the function kthread_run() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check
should be replaced with IS_ERR().

Link: http://lkml.kernel.org/r/1466184839-14927-1-git-send-email-weiyj_lk@163.com

Cc: stable@vger.kernel.org
Fixes: 6c43e554a ("ring-buffer: Add ring buffer startup selftest")
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-05 09:36:52 -04:00
Keith Busch
7bf8222b9b irq/affinity: Fix CPU spread for unbalanced nodes
The irq_create_affinity_masks routine is responsible for assigning a
number of interrupt vectors to CPUs. The optimal assignemnet will spread
requested vectors to all CPUs, with the fewest CPUs sharing a vector.

The algorithm may fail to assign some vectors to any CPUs if a node's
CPU count is lower than the average number of vectors per node. These
vectors are unusable and create an un-optimal spread.

Recalculate the number of vectors to assign at each node iteration by using
the remaining number of vectors and nodes to be assigned, not exceeding the
number of CPUs in that node. This will guarantee that every CPU is assigned
at least one vector.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: linux-nvme@lists.infradead.org
Link: http://lkml.kernel.org/r/1491247553-7603-1-git-send-email-keith.busch@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-04-04 11:57:28 +02:00
Linus Torvalds
128c434a70 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
 "This update provides:

   - make the scheduler clock switch to unstable mode smooth so the
     timestamps stay at microseconds granularity instead of switching to
     tick granularity.

   - unbreak perf test tsc by taking the new offset into account which
     was added in order to proveide better sched clock continuity

   - switching sched clock to unstable mode runs all clock related
     computations which affect the sched clock output itself from a work
     queue. In case of preemption sched clock uses half updated data and
     provides wrong timestamps. Keep the math in the protected context
     and delegate only the static key switch to workqueue context.

   - remove a duplicate header include"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/headers: Remove duplicate #include <linux/sched/debug.h> line
  sched/clock: Fix broken stable to unstable transfer
  sched/clock, x86/perf: Fix "perf test tsc"
  sched/clock: Fix clear_sched_clock_stable() preempt wobbly
2017-04-02 09:25:10 -07:00
Daniel Borkmann
79adffcd64 bpf, verifier: fix rejection of unaligned access checks for map_value_adj
Currently, the verifier doesn't reject unaligned access for map_value_adj
register types. Commit 484611357c ("bpf: allow access into map value
arrays") added logic to check_ptr_alignment() extending it from PTR_TO_PACKET
to also PTR_TO_MAP_VALUE_ADJ, but for PTR_TO_MAP_VALUE_ADJ no enforcement
is in place, because reg->id for PTR_TO_MAP_VALUE_ADJ reg types is never
non-zero, meaning, we can cause BPF_H/_W/_DW-based unaligned access for
architectures not supporting efficient unaligned access, and thus worst
case could raise exceptions on some archs that are unable to correct the
unaligned access or perform a different memory access to the actual
requested one and such.

i) Unaligned load with !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
   on r0 (map_value_adj):

   0: (bf) r2 = r10
   1: (07) r2 += -8
   2: (7a) *(u64 *)(r2 +0) = 0
   3: (18) r1 = 0x42533a00
   5: (85) call bpf_map_lookup_elem#1
   6: (15) if r0 == 0x0 goto pc+11
    R0=map_value(ks=8,vs=48,id=0),min_value=0,max_value=0 R10=fp
   7: (61) r1 = *(u32 *)(r0 +0)
   8: (35) if r1 >= 0xb goto pc+9
    R0=map_value(ks=8,vs=48,id=0),min_value=0,max_value=0 R1=inv,min_value=0,max_value=10 R10=fp
   9: (07) r0 += 3
  10: (79) r7 = *(u64 *)(r0 +0)
    R0=map_value_adj(ks=8,vs=48,id=0),min_value=3,max_value=3 R1=inv,min_value=0,max_value=10 R10=fp
  11: (79) r7 = *(u64 *)(r0 +2)
    R0=map_value_adj(ks=8,vs=48,id=0),min_value=3,max_value=3 R1=inv,min_value=0,max_value=10 R7=inv R10=fp
  [...]

ii) Unaligned store with !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
    on r0 (map_value_adj):

   0: (bf) r2 = r10
   1: (07) r2 += -8
   2: (7a) *(u64 *)(r2 +0) = 0
   3: (18) r1 = 0x4df16a00
   5: (85) call bpf_map_lookup_elem#1
   6: (15) if r0 == 0x0 goto pc+19
    R0=map_value(ks=8,vs=48,id=0),min_value=0,max_value=0 R10=fp
   7: (07) r0 += 3
   8: (7a) *(u64 *)(r0 +0) = 42
    R0=map_value_adj(ks=8,vs=48,id=0),min_value=3,max_value=3 R10=fp
   9: (7a) *(u64 *)(r0 +2) = 43
    R0=map_value_adj(ks=8,vs=48,id=0),min_value=3,max_value=3 R10=fp
  10: (7a) *(u64 *)(r0 -2) = 44
    R0=map_value_adj(ks=8,vs=48,id=0),min_value=3,max_value=3 R10=fp
  [...]

For the PTR_TO_PACKET type, reg->id is initially zero when skb->data
was fetched, it later receives a reg->id from env->id_gen generator
once another register with UNKNOWN_VALUE type was added to it via
check_packet_ptr_add(). The purpose of this reg->id is twofold: i) it
is used in find_good_pkt_pointers() for setting the allowed access
range for regs with PTR_TO_PACKET of same id once verifier matched
on data/data_end tests, and ii) for check_ptr_alignment() to determine
that when not having efficient unaligned access and register with
UNKNOWN_VALUE was added to PTR_TO_PACKET, that we're only allowed
to access the content bytewise due to unknown unalignment. reg->id
was never intended for PTR_TO_MAP_VALUE{,_ADJ} types and thus is
always zero, the only marking is in PTR_TO_MAP_VALUE_OR_NULL that
was added after 484611357c via 57a09bf0a4 ("bpf: Detect identical
PTR_TO_MAP_VALUE_OR_NULL registers"). Above tests will fail for
non-root environment due to prohibited pointer arithmetic.

The fix splits register-type specific checks into their own helper
instead of keeping them combined, so we don't run into a similar
issue in future once we extend check_ptr_alignment() further and
forget to add reg->type checks for some of the checks.

Fixes: 484611357c ("bpf: allow access into map value arrays")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01 12:36:37 -07:00
Daniel Borkmann
fce366a9dd bpf, verifier: fix alu ops against map_value{, _adj} register types
While looking into map_value_adj, I noticed that alu operations
directly on the map_value() resp. map_value_adj() register (any
alu operation on a map_value() register will turn it into a
map_value_adj() typed register) are not sufficiently protected
against some of the operations. Two non-exhaustive examples are
provided that the verifier needs to reject:

 i) BPF_AND on r0 (map_value_adj):

  0: (bf) r2 = r10
  1: (07) r2 += -8
  2: (7a) *(u64 *)(r2 +0) = 0
  3: (18) r1 = 0xbf842a00
  5: (85) call bpf_map_lookup_elem#1
  6: (15) if r0 == 0x0 goto pc+2
   R0=map_value(ks=8,vs=48,id=0),min_value=0,max_value=0 R10=fp
  7: (57) r0 &= 8
  8: (7a) *(u64 *)(r0 +0) = 22
   R0=map_value_adj(ks=8,vs=48,id=0),min_value=0,max_value=8 R10=fp
  9: (95) exit

  from 6 to 9: R0=inv,min_value=0,max_value=0 R10=fp
  9: (95) exit
  processed 10 insns

ii) BPF_ADD in 32 bit mode on r0 (map_value_adj):

  0: (bf) r2 = r10
  1: (07) r2 += -8
  2: (7a) *(u64 *)(r2 +0) = 0
  3: (18) r1 = 0xc24eee00
  5: (85) call bpf_map_lookup_elem#1
  6: (15) if r0 == 0x0 goto pc+2
   R0=map_value(ks=8,vs=48,id=0),min_value=0,max_value=0 R10=fp
  7: (04) (u32) r0 += (u32) 0
  8: (7a) *(u64 *)(r0 +0) = 22
   R0=map_value_adj(ks=8,vs=48,id=0),min_value=0,max_value=0 R10=fp
  9: (95) exit

  from 6 to 9: R0=inv,min_value=0,max_value=0 R10=fp
  9: (95) exit
  processed 10 insns

Issue is, while min_value / max_value boundaries for the access
are adjusted appropriately, we change the pointer value in a way
that cannot be sufficiently tracked anymore from its origin.
Operations like BPF_{AND,OR,DIV,MUL,etc} on a destination register
that is PTR_TO_MAP_VALUE{,_ADJ} was probably unintended, in fact,
all the test cases coming with 484611357c ("bpf: allow access
into map value arrays") perform BPF_ADD only on the destination
register that is PTR_TO_MAP_VALUE_ADJ.

Only for UNKNOWN_VALUE register types such operations make sense,
f.e. with unknown memory content fetched initially from a constant
offset from the map value memory into a register. That register is
then later tested against lower / upper bounds, so that the verifier
can then do the tracking of min_value / max_value, and properly
check once that UNKNOWN_VALUE register is added to the destination
register with type PTR_TO_MAP_VALUE{,_ADJ}. This is also what the
original use-case is solving. Note, tracking on what is being
added is done through adjust_reg_min_max_vals() and later access
to the map value enforced with these boundaries and the given offset
from the insn through check_map_access_adj().

Tests will fail for non-root environment due to prohibited pointer
arithmetic, in particular in check_alu_op(), we bail out on the
is_pointer_value() check on the dst_reg (which is false in root
case as we allow for pointer arithmetic via env->allow_ptr_leaks).

Similarly to PTR_TO_PACKET, one way to fix it is to restrict the
allowed operations on PTR_TO_MAP_VALUE{,_ADJ} registers to 64 bit
mode BPF_ADD. The test_verifier suite runs fine after the patch
and it also rejects mentioned test cases.

Fixes: 484611357c ("bpf: allow access into map value arrays")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01 12:36:37 -07:00
Linus Torvalds
035f0cd3f8 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
 "This fixes the following issues:

   - memory corruption when kmalloc fails in xts/lrw

   - mark some CCP DMA channels as private

   - fix reordering race in padata

   - regression in omap-rng DT description"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: xts,lrw - fix out-of-bounds write after kmalloc failure
  crypto: ccp - Make some CCP DMA channels private
  padata: avoid race in reordering
  dt-bindings: rng: clocks property on omap_rng not always mandatory
2017-03-31 12:11:32 -07:00
Dave Airlie
e5c1ff1475 Linux 4.11-rc4
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Backmerge tag 'v4.11-rc4' into drm-next

Linux 4.11-rc4

The i915 GVT team need the rc4 code to base some more code on.
2017-03-28 17:34:19 +10:00
Paul Moore
ab6434a137 audit: move audit_signal_info() into kernel/auditsc.c
Commit 5b52330bbf ("audit: fix auditd/kernel connection state
tracking") made inlining audit_signal_info() a bit pointless as
it was always calling into auditd_test_task() so let's remove the
inline function in kernel/audit.h and convert __audit_signal_info()
in kernel/auditsc.c into audit_signal_info().

Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-27 14:30:06 -04:00
Pavel Tatashin
7b09cc5a9d sched/clock: Fix broken stable to unstable transfer
When it is determined that the clock is actually unstable, and
we switch from stable to unstable, the __clear_sched_clock_stable()
function is eventually called.

In this function we set gtod_offset so the following holds true:

  sched_clock() + raw_offset == ktime_get_ns() + gtod_offset

But instead of getting the latest timestamps, we use the last values
from scd, so instead of sched_clock() we use scd->tick_raw, and
instead of ktime_get_ns() we use scd->tick_gtod.

However, later, when we use gtod_offset sched_clock_local() we do not
add it to scd->tick_gtod to calculate the correct clock value when we
determine the boundaries for min/max clocks.

This can result in tick granularity sched_clock() values, so fix it.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: hpa@zytor.com
Fixes: 5680d8094f ("sched/clock: Provide better clock continuity")
Link: http://lkml.kernel.org/r/1490214265-899964-2-git-send-email-pasha.tatashin@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-27 10:23:48 +02:00
Linus Torvalds
4c3de7e5bf Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit
Pull audit fix from Paul Moore:
 "We've got an audit fix, and unfortunately it is big.

  While I'm not excited that we need to be sending you something this
  large during the -rcX phase, it does fix some very real, and very
  tangled, problems relating to locking, backlog queues, and the audit
  daemon connection.

  This code has passed our testsuite without problem and it has held up
  to my ad-hoc stress tests (arguably better than the existing code),
  please consider pulling this as fix for the next v4.11-rcX tag"

* 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit:
  audit: fix auditd/kernel connection state tracking
2017-03-25 15:13:55 -07:00
Alexei Starovoitov
b1977682a3 bpf: improve verifier packet range checks
llvm can optimize the 'if (ptr > data_end)' checks to be in the order
slightly different than the original C code which will confuse verifier.
Like:
if (ptr + 16 > data_end)
  return TC_ACT_SHOT;
// may be followed by
if (ptr + 14 > data_end)
  return TC_ACT_SHOT;
while llvm can see that 'ptr' is valid for all 16 bytes,
the verifier could not.
Fix verifier logic to account for such case and add a test.

Reported-by: Huapeng Zhou <hzhou@fb.com>
Fixes: 969bf05eb3 ("bpf: direct packet access")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24 20:51:28 -07:00
Jason A. Donenfeld
de5540d088 padata: avoid race in reordering
Under extremely heavy uses of padata, crashes occur, and with list
debugging turned on, this happens instead:

[87487.298728] WARNING: CPU: 1 PID: 882 at lib/list_debug.c:33
__list_add+0xae/0x130
[87487.301868] list_add corruption. prev->next should be next
(ffffb17abfc043d0), but was ffff8dba70872c80. (prev=ffff8dba70872b00).
[87487.339011]  [<ffffffff9a53d075>] dump_stack+0x68/0xa3
[87487.342198]  [<ffffffff99e119a1>] ? console_unlock+0x281/0x6d0
[87487.345364]  [<ffffffff99d6b91f>] __warn+0xff/0x140
[87487.348513]  [<ffffffff99d6b9aa>] warn_slowpath_fmt+0x4a/0x50
[87487.351659]  [<ffffffff9a58b5de>] __list_add+0xae/0x130
[87487.354772]  [<ffffffff9add5094>] ? _raw_spin_lock+0x64/0x70
[87487.357915]  [<ffffffff99eefd66>] padata_reorder+0x1e6/0x420
[87487.361084]  [<ffffffff99ef0055>] padata_do_serial+0xa5/0x120

padata_reorder calls list_add_tail with the list to which its adding
locked, which seems correct:

spin_lock(&squeue->serial.lock);
list_add_tail(&padata->list, &squeue->serial.list);
spin_unlock(&squeue->serial.lock);

This therefore leaves only place where such inconsistency could occur:
if padata->list is added at the same time on two different threads.
This pdata pointer comes from the function call to
padata_get_next(pd), which has in it the following block:

next_queue = per_cpu_ptr(pd->pqueue, cpu);
padata = NULL;
reorder = &next_queue->reorder;
if (!list_empty(&reorder->list)) {
       padata = list_entry(reorder->list.next,
                           struct padata_priv, list);
       spin_lock(&reorder->lock);
       list_del_init(&padata->list);
       atomic_dec(&pd->reorder_objects);
       spin_unlock(&reorder->lock);

       pd->processed++;

       goto out;
}
out:
return padata;

I strongly suspect that the problem here is that two threads can race
on reorder list. Even though the deletion is locked, call to
list_entry is not locked, which means it's feasible that two threads
pick up the same padata object and subsequently call list_add_tail on
them at the same time. The fix is thus be hoist that lock outside of
that block.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-03-24 21:51:33 +08:00
Linus Torvalds
ebe64824e9 Power management fixes for v4.11-rc4
- Make intel_pstate use one set of global P-state limits in the
    active mode regardless of the scaling_governor settings for
    individual CPUs instead of switching back and forth between two
    of them in a way that is hard to control (Rafael Wysocki).
 
  - Drop a useless function from intel_pstate to prevent it from
    modifying the maximum supported frequency value unexpectedly
    which may confuse the cpufreq core (Rafael Wysocki).
 
  - Fix the cpufreq core to restore policy limits on CPU online so
    that the limits are not reset over system suspend/resume, among
    other things (Viresh Kumar).
 
  - Fix the initialization of the schedutil cpufreq governor to
    make the IO-wait boosting mechanism in it actually work on
    systems with one CPU per cpufreq policy (Rafael Wysocki).
 
  - Add a sanity check to the cpuidle core to prevent crashes from
    happening if the architecture code initialization fails to set
    up things as expected (Vaidyanathan Srinivasan).
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Merge tag 'pm-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "One of these is an intel_pstate regression fix and it is not a small
  change, but it mostly removes code that shouldn't be there. That code
  was acquired by mistake and has been a source of constant pain since
  then, so the time has come to get rid of it finally. We have not seen
  problems with this change in the lab, so fingers crossed.

  The rest is more usual: one more intel_pstate commit removing useless
  code, a cpufreq core fix to make it restore policy limits on CPU
  online (which prevents the limits from being reset over system
  suspend/resume), a schedutil cpufreq governor initialization fix to
  make it actually work as advertised on all systems and an extra sanity
  check in the cpuidle core to prevent crashes from happening if the
  arch code messes things up.

  Specifics:

   - Make intel_pstate use one set of global P-state limits in the
     active mode regardless of the scaling_governor settings for
     individual CPUs instead of switching back and forth between two of
     them in a way that is hard to control (Rafael Wysocki).

   - Drop a useless function from intel_pstate to prevent it from
     modifying the maximum supported frequency value unexpectedly which
     may confuse the cpufreq core (Rafael Wysocki).

   - Fix the cpufreq core to restore policy limits on CPU online so that
     the limits are not reset over system suspend/resume, among other
     things (Viresh Kumar).

   - Fix the initialization of the schedutil cpufreq governor to make
     the IO-wait boosting mechanism in it actually work on systems with
     one CPU per cpufreq policy (Rafael Wysocki).

   - Add a sanity check to the cpuidle core to prevent crashes from
     happening if the architecture code initialization fails to set up
     things as expected (Vaidyanathan Srinivasan)"

* tag 'pm-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: Restore policy min/max limits on CPU online
  cpuidle: Validate cpu_dev in cpuidle_add_sysfs()
  cpufreq: intel_pstate: Fix policy data management in passive mode
  cpufreq: schedutil: Fix per-CPU structure initialization in sugov_start()
  cpufreq: intel_pstate: One set of global limits in active mode
2017-03-23 20:00:39 -07:00
Linus Torvalds
f341d9f08a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Several netfilter fixes from Pablo and the crew:
      - Handle fragmented packets properly in netfilter conntrack, from
        Florian Westphal.
      - Fix SCTP ICMP packet handling, from Ying Xue.
      - Fix big-endian bug in nftables, from Liping Zhang.
      - Fix alignment of fake conntrack entry, from Steven Rostedt.

 2) Fix feature flags setting in fjes driver, from Taku Izumi.

 3) Openvswitch ipv6 tunnel source address not set properly, from Or
    Gerlitz.

 4) Fix jumbo MTU handling in amd-xgbe driver, from Thomas Lendacky.

 5) sk->sk_frag.page not released properly in some cases, from Eric
    Dumazet.

 6) Fix RTNL deadlocks in nl80211, from Johannes Berg.

 7) Fix erroneous RTNL lockdep splat in crypto, from Herbert Xu.

 8) Cure improper inflight handling during AF_UNIX GC, from Andrey
    Ulanov.

 9) sch_dsmark doesn't write to packet headers properly, from Eric
    Dumazet.

10) Fix SCM_TIMESTAMPING_OPT_STATS handling in TCP, from Soheil Hassas
    Yeganeh.

11) Add some IDs for Motorola qmi_wwan chips, from Tony Lindgren.

12) Fix nametbl deadlock in tipc, from Ying Xue.

13) GRO and LRO packets not counted correctly in mlx5 driver, from Gal
    Pressman.

14) Fix reset of internal PHYs in bcmgenet, from Doug Berger.

15) Fix hashmap allocation handling, from Alexei Starovoitov.

16) nl_fib_input() needs stronger netlink message length checking, from
    Eric Dumazet.

17) Fix double-free of sk->sk_filter during sock clone, from Daniel
    Borkmann.

18) Fix RX checksum offloading in aquantia driver, from Pavel Belous.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (85 commits)
  net:ethernet:aquantia: Fix for RX checksum offload.
  amd-xgbe: Fix the ECC-related bit position definitions
  sfc: cleanup a condition in efx_udp_tunnel_del()
  Bluetooth: btqcomsmd: fix compile-test dependency
  inet: frag: release spinlock before calling icmp_send()
  tcp: initialize icsk_ack.lrcvtime at session start time
  genetlink: fix counting regression on ctrl_dumpfamily()
  socket, bpf: fix sk_filter use after free in sk_clone_lock
  ipv4: provide stronger user input validation in nl_fib_input()
  bpf: fix hashmap extra_elems logic
  enic: update enic maintainers
  net: bcmgenet: remove bcmgenet_internal_phy_setup()
  ipv6: make sure to initialize sockc.tsflags before first use
  fjes: Do not load fjes driver if extended socket device is not power on.
  fjes: Do not load fjes driver if system does not have extended socket device.
  net/mlx5e: Count LRO packets correctly
  net/mlx5e: Count GSO packets correctly
  net/mlx5: Increase number of max QPs in default profile
  net/mlx5e: Avoid supporting udp tunnel port ndo for VF reps
  net/mlx5e: Use the proper UAPI values when offloading TC vlan actions
  ...
2017-03-23 11:29:49 -07:00
Peter Zijlstra
698eff6355 sched/clock, x86/perf: Fix "perf test tsc"
People reported that commit:

  5680d8094f ("sched/clock: Provide better clock continuity")

broke "perf test tsc".

That commit added another offset to the reported clock value; so
take that into account when computing the provided offset values.

Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 5680d8094f ("sched/clock: Provide better clock continuity")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-23 07:31:49 +01:00
Peter Zijlstra
71fdb70eb4 sched/clock: Fix clear_sched_clock_stable() preempt wobbly
Paul reported a problems with clear_sched_clock_stable(). Since we run
all of __clear_sched_clock_stable() from workqueue context, there's a
preempt problem.

Solve it by only running the static_key_disable() from workqueue.

Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Link: http://lkml.kernel.org/r/20170313124621.GA3328@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-23 07:31:48 +01:00
Dave Airlie
65d1086c44 Linux 4.11-rc3
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BackMerge tag 'v4.11-rc3' into drm-next

Linux 4.11-rc3 as requested by Daniel
2017-03-23 12:05:13 +10:00
Alexei Starovoitov
8c290e60fa bpf: fix hashmap extra_elems logic
In both kmalloc and prealloc mode the bpf_map_update_elem() is using
per-cpu extra_elems to do atomic update when the map is full.
There are two issues with it. The logic can be misused, since it allows
max_entries+num_cpus elements to be present in the map. And alloc_extra_elems()
at map creation time can fail percpu alloc for large map values with a warn:
WARNING: CPU: 3 PID: 2752 at ../mm/percpu.c:892 pcpu_alloc+0x119/0xa60
illegal size (32824) or align (8) for percpu allocation

The fixes for both of these issues are different for kmalloc and prealloc modes.
For prealloc mode allocate extra num_possible_cpus elements and store
their pointers into extra_elems array instead of actual elements.
Hence we can use these hidden(spare) elements not only when the map is full
but during bpf_map_update_elem() that replaces existing element too.
That also improves performance, since pcpu_freelist_pop/push is avoided.
Unfortunately this approach cannot be used for kmalloc mode which needs
to kfree elements after rcu grace period. Therefore switch it back to normal
kmalloc even when full and old element exists like it was prior to
commit 6c90598174 ("bpf: pre-allocate hash map elements").

Add tests to check for over max_entries and large map values.

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 6c90598174 ("bpf: pre-allocate hash map elements")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22 14:12:18 -07:00
Paul Moore
5b52330bbf audit: fix auditd/kernel connection state tracking
What started as a rather straightforward race condition reported by
Dmitry using the syzkaller fuzzer ended up revealing some major
problems with how the audit subsystem managed its netlink sockets and
its connection with the userspace audit daemon.  Fixing this properly
had quite the cascading effect and what we are left with is this rather
large and complicated patch.  My initial goal was to try and decompose
this patch into multiple smaller patches, but the way these changes
are intertwined makes it difficult to split these changes into
meaningful pieces that don't break or somehow make things worse for
the intermediate states.

The patch makes a number of changes, but the most significant are
highlighted below:

* The auditd tracking variables, e.g. audit_sock, are now gone and
replaced by a RCU/spin_lock protected variable auditd_conn which is
a structure containing all of the auditd tracking information.

* We no longer track the auditd sock directly, instead we track it
via the network namespace in which it resides and we use the audit
socket associated with that namespace.  In spirit, this is what the
code was trying to do prior to this patch (at least I think that is
what the original authors intended), but it was done rather poorly
and added a layer of obfuscation that only masked the underlying
problems.

* Big backlog queue cleanup, again.  In v4.10 we made some pretty big
changes to how the audit backlog queues work, here we haven't changed
the queue design so much as cleaned up the implementation.  Brought
about by the locking changes, we've simplified kauditd_thread() quite
a bit by consolidating the queue handling into a new helper function,
kauditd_send_queue(), which allows us to eliminate a lot of very
similar code and makes the looping logic in kauditd_thread() clearer.

* All netlink messages sent to auditd are now sent via
auditd_send_unicast_skb().  Other than just making sense, this makes
the lock handling easier.

* Change the audit_log_start() sleep behavior so that we never sleep
on auditd events (unchanged) or if the caller is holding the
audit_cmd_mutex (changed).  Previously we didn't sleep if the caller
was auditd or if the message type fell between a certain range; the
type check was a poor effort of doing what the cmd_mutex check now
does.  Richard Guy Briggs originally proposed not sleeping the
cmd_mutex owner several years ago but his patch wasn't acceptable
at the time.  At least the idea lives on here.

* A problem with the lost record counter has been resolved.  Steve
Grubb and I both happened to notice this problem and according to
some quick testing by Steve, this problem goes back quite some time.
It's largely a harmless problem, although it may have left some
careful sysadmins quite puzzled.

Cc: <stable@vger.kernel.org> # 4.10.x-
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-21 11:26:35 -04:00
Rafael J. Wysocki
4296f23ed4 cpufreq: schedutil: Fix per-CPU structure initialization in sugov_start()
sugov_start() only initializes struct sugov_cpu per-CPU structures
for shared policies, but it should do that for single-CPU policies too.

That in particular makes the IO-wait boost mechanism work in the
cases when cpufreq policies correspond to individual CPUs.

Fixes: 21ca6d2c52 (cpufreq: schedutil: Add iowait boosting)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.9+ <stable@vger.kernel.org> # 4.9+
2017-03-21 01:03:08 +01:00
Linus Torvalds
3e51f893de Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull CPU hotplug fix from Thomas Gleixner:
 "A single fix preventing the concurrent execution of the CPU hotplug
  callback install/invocation machinery. Long standing bug caused by a
  massive brain slip of that Gleixner dude, which went unnoticed for
  almost a year"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Serialize callback invocations proper
2017-03-18 08:33:44 -07:00
Linus Torvalds
a7fc726bb2 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "A set of perf related fixes:

   - fix a CR4.PCE propagation issue caused by usage of mm instead of
     active_mm and therefore propagated the wrong value.

   - perf core fixes, which plug a use-after-free issue and make the
     event inheritance on fork more robust.

   - a tooling fix for symbol handling"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf symbols: Fix symbols__fixup_end heuristic for corner cases
  x86/perf: Clarify why x86_pmu_event_mapped() isn't racy
  x86/perf: Fix CR4.PCE propagation to use active_mm instead of mm
  perf/core: Better explain the inherit magic
  perf/core: Simplify perf_event_free_task()
  perf/core: Fix event inheritance on fork()
  perf/core: Fix use-after-free in perf_release()
2017-03-17 13:59:52 -07:00
Linus Torvalds
cd21debe53 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
 "From the scheduler departement:

   - a bunch of sched deadline related fixes which deal with various
     buglets and corner cases.

   - two fixes for the loadavg spikes which are caused by the delayed
     NOHZ accounting"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Use deadline instead of period when calculating overflow
  sched/deadline: Throttle a constrained deadline task activated after the deadline
  sched/deadline: Make sure the replenishment timer fires in the next period
  sched/loadavg: Use {READ,WRITE}_ONCE() for sample window
  sched/loadavg: Avoid loadavg spikes caused by delayed NO_HZ accounting
  sched/deadline: Add missing update_rq_clock() in dl_task_timer()
2017-03-17 13:19:07 -07:00
Linus Torvalds
b5f13082b1 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
 "Three fixes related to locking:

   - fix a SIGKILL issue for RWSEM_GENERIC_SPINLOCK which has been fixed
     for the XCHGADD variant already

   - plug a potential use after free in the futex code

   - prevent leaking a held spinlock in an futex error handling code
     path"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Fix down_write_killable() for CONFIG_RWSEM_GENERIC_SPINLOCK=y
  futex: Add missing error handling to FUTEX_REQUEUE_PI
  futex: Fix potential use-after-free in FUTEX_REQUEUE_PI
2017-03-17 13:16:24 -07:00
Tejun Heo
77f88796ce cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups
Creation of a kthread goes through a couple interlocked stages between
the kthread itself and its creator.  Once the new kthread starts
running, it initializes itself and wakes up the creator.  The creator
then can further configure the kthread and then let it start doing its
job by waking it up.

In this configuration-by-creator stage, the creator is the only one
that can wake it up but the kthread is visible to userland.  When
altering the kthread's attributes from userland is allowed, this is
fine; however, for cases where CPU affinity is critical,
kthread_bind() is used to first disable affinity changes from userland
and then set the affinity.  This also prevents the kthread from being
migrated into non-root cgroups as that can affect the CPU affinity and
many other things.

Unfortunately, the cgroup side of protection is racy.  While the
PF_NO_SETAFFINITY flag prevents further migrations, userland can win
the race before the creator sets the flag with kthread_bind() and put
the kthread in a non-root cgroup, which can lead to all sorts of
problems including incorrect CPU affinity and starvation.

This bug got triggered by userland which periodically tries to migrate
all processes in the root cpuset cgroup to a non-root one.  Per-cpu
workqueue workers got caught while being created and ended up with
incorrected CPU affinity breaking concurrency management and sometimes
stalling workqueue execution.

This patch adds task->no_cgroup_migration which disallows the task to
be migrated by userland.  kthreadd starts with the flag set making
every child kthread start in the root cgroup with migration
disallowed.  The flag is cleared after the kthread finishes
initialization by which time PF_NO_SETAFFINITY is set if the kthread
should stay in the root cgroup.

It'd be better to wait for the initialization instead of failing but I
couldn't think of a way of implementing that without adding either a
new PF flag, or sleeping and retrying from waiting side.  Even if
userland depends on changing cgroup membership of a kthread, it either
has to be synchronized with kthread_create() or periodically repeat,
so it's unlikely that this would break anything.

v2: Switch to a simpler implementation using a new task_struct bit
    field suggested by Oleg.

Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-and-debugged-by: Chris Mason <clm@fb.com>
Cc: stable@vger.kernel.org # v4.3+ (we can't close the race on < v4.3)
Signed-off-by: Tejun Heo <tj@kernel.org>
2017-03-17 10:18:47 -04:00
Heiko Carstens
55adc1d05d mm: add private lock to serialize memory hotplug operations
Commit bfc8c90139 ("mem-hotplug: implement get/put_online_mems")
introduced new functions get/put_online_mems() and mem_hotplug_begin/end()
in order to allow similar semantics for memory hotplug like for cpu
hotplug.

The corresponding functions for cpu hotplug are get/put_online_cpus()
and cpu_hotplug_begin/done() for cpu hotplug.

The commit however missed to introduce functions that would serialize
memory hotplug operations like they are done for cpu hotplug with
cpu_maps_update_begin/done().

This basically leaves mem_hotplug.active_writer unprotected and allows
concurrent writers to modify it, which may lead to problems as outlined
by commit f931ab479d ("mm: fix devm_memremap_pages crash, use
mem_hotplug_{begin, done}").

That commit was extended again with commit b5d24fda9c ("mm,
devm_memremap_pages: hold device_hotplug lock over mem_hotplug_{begin,
done}") which serializes memory hotplug operations for some call sites
by using the device_hotplug lock.

In addition with commit 3fc2192410 ("mm: validate device_hotplug is held
for memory hotplug") a sanity check was added to mem_hotplug_begin() to
verify that the device_hotplug lock is held.

This in turn triggers the following warning on s390:

WARNING: CPU: 6 PID: 1 at drivers/base/core.c:643 assert_held_device_hotplug+0x4a/0x58
 Call Trace:
  assert_held_device_hotplug+0x40/0x58)
  mem_hotplug_begin+0x34/0xc8
  add_memory_resource+0x7e/0x1f8
  add_memory+0xda/0x130
  add_memory_merged+0x15c/0x178
  sclp_detect_standby_memory+0x2ae/0x2f8
  do_one_initcall+0xa2/0x150
  kernel_init_freeable+0x228/0x2d8
  kernel_init+0x2a/0x140
  kernel_thread_starter+0x6/0xc

One possible fix would be to add more lock_device_hotplug() and
unlock_device_hotplug() calls around each call site of
mem_hotplug_begin/end().  But that would give the device_hotplug lock
additional semantics it better should not have (serialize memory hotplug
operations).

Instead add a new memory_add_remove_lock which has the similar semantics
like cpu_add_remove_lock for cpu hotplug.

To keep things hopefully a bit easier the lock will be locked and unlocked
within the mem_hotplug_begin/end() functions.

Link: http://lkml.kernel.org/r/20170314125226.16779-2-heiko.carstens@de.ibm.com
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-16 16:56:18 -07:00
Peter Zijlstra
d8a8cfc769 perf/core: Better explain the inherit magic
While going through the event inheritance code Oleg got confused.

Add some comments to better explain the silent dissapearance of
orphaned events.

So what happens is that at perf_event_release_kernel() time; when an
event looses its connection to userspace (and ceases to exist from the
user's perspective) we can still have an arbitrary amount of inherited
copies of the event. We want to synchronously find and remove all
these child events.

Since that requires a bit of lock juggling, there is the possibility
that concurrent clone()s will create new child events. Therefore we
first mark the parent event as DEAD, which marks all the extant child
events as orphaned.

We then avoid copying orphaned events; in order to avoid getting more
of them.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: fweisbec@gmail.com
Link: http://lkml.kernel.org/r/20170316125823.289567442@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16 14:16:53 +01:00
Peter Zijlstra
15121c789e perf/core: Simplify perf_event_free_task()
We have ctx->event_list that contains all events; no need to
repeatedly iterate the group lists to find them all.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: fweisbec@gmail.com
Link: http://lkml.kernel.org/r/20170316125823.239678244@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16 14:16:53 +01:00
Peter Zijlstra
e7cc4865f0 perf/core: Fix event inheritance on fork()
While hunting for clues to a use-after-free, Oleg spotted that
perf_event_init_context() can loose an error value with the result
that fork() can succeed even though we did not fully inherit the perf
event context.

Spotted-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: oleg@redhat.com
Cc: stable@vger.kernel.org
Fixes: 889ff01506 ("perf/core: Split context's event group list into pinned and non-pinned lists")
Link: http://lkml.kernel.org/r/20170316125823.190342547@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16 14:16:52 +01:00
Peter Zijlstra
e552a8389a perf/core: Fix use-after-free in perf_release()
Dmitry reported syzcaller tripped a use-after-free in perf_release().

After much puzzlement Oleg spotted the below scenario:

  Task1                           Task2

  fork()
    perf_event_init_task()
    /* ... */
    goto bad_fork_$foo;
    /* ... */
    perf_event_free_task()
      mutex_lock(ctx->lock)
      perf_free_event(B)

                                  perf_event_release_kernel(A)
                                    mutex_lock(A->child_mutex)
                                    list_for_each_entry(child, ...) {
                                      /* child == B */
                                      ctx = B->ctx;
                                      get_ctx(ctx);
                                      mutex_unlock(A->child_mutex);

        mutex_lock(A->child_mutex)
        list_del_init(B->child_list)
        mutex_unlock(A->child_mutex)

        /* ... */

      mutex_unlock(ctx->lock);
      put_ctx() /* >0 */
    free_task();
                                      mutex_lock(ctx->lock);
                                      mutex_lock(A->child_mutex);
                                      /* ... */
                                      mutex_unlock(A->child_mutex);
                                      mutex_unlock(ctx->lock)
                                      put_ctx() /* 0 */
                                        ctx->task && !TOMBSTONE
                                          put_task_struct() /* UAF */

This patch closes the hole by making perf_event_free_task() destroy the
task <-> ctx relation such that perf_event_release_kernel() will no longer
observe the now dead task.

Spotted-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: fweisbec@gmail.com
Cc: oleg@redhat.com
Cc: stable@vger.kernel.org
Fixes: c6e5b73242 ("perf: Synchronously clean up child events")
Link: http://lkml.kernel.org/r/20170314155949.GE32474@worktop
Link: http://lkml.kernel.org/r/20170316125823.140295131@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16 14:16:52 +01:00