Commit Graph

58002 Commits

Author SHA1 Message Date
Linus Torvalds
2c6a392cdd Merge branch 'core-stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull stack trace updates from Ingo Molnar:
 "So Thomas looked at the stacktrace code recently and noticed a few
  weirdnesses, and we all know how such stories of crummy kernel code
  meeting German engineering perfection end: a 45-patch series to clean
  it all up! :-)

  Here's the changes in Thomas's words:

   'Struct stack_trace is a sinkhole for input and output parameters
    which is largely pointless for most usage sites. In fact if embedded
    into other data structures it creates indirections and extra storage
    overhead for no benefit.

    Looking at all usage sites makes it clear that they just require an
    interface which is based on a storage array. That array is either on
    stack, global or embedded into some other data structure.

    Some of the stack depot usage sites are outright wrong, but
    fortunately the wrongness just causes more stack being used for
    nothing and does not have functional impact.

    Another oddity is the inconsistent termination of the stack trace
    with ULONG_MAX. It's pointless as the number of entries is what
    determines the length of the stored trace. In fact quite some call
    sites remove the ULONG_MAX marker afterwards with or without nasty
    comments about it. Not all architectures do that and those which do,
    do it inconsistenly either conditional on nr_entries == 0 or
    unconditionally.

    The following series cleans that up by:

      1) Removing the ULONG_MAX termination in the architecture code

      2) Removing the ULONG_MAX fixups at the call sites

      3) Providing plain storage array based interfaces for stacktrace
         and stackdepot.

      4) Cleaning up the mess at the callsites including some related
         cleanups.

      5) Removing the struct stack_trace based interfaces

    This is not changing the struct stack_trace interfaces at the
    architecture level, but it removes the exposure to the generic
    code'"

* 'core-stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
  x86/stacktrace: Use common infrastructure
  stacktrace: Provide common infrastructure
  lib/stackdepot: Remove obsolete functions
  stacktrace: Remove obsolete functions
  livepatch: Simplify stack trace retrieval
  tracing: Remove the last struct stack_trace usage
  tracing: Simplify stack trace retrieval
  tracing: Make ftrace_trace_userstack() static and conditional
  tracing: Use percpu stack trace buffer more intelligently
  tracing: Simplify stacktrace retrieval in histograms
  lockdep: Simplify stack trace handling
  lockdep: Remove save argument from check_prev_add()
  lockdep: Remove unused trace argument from print_circular_bug()
  drm: Simplify stacktrace handling
  dm persistent data: Simplify stack trace handling
  dm bufio: Simplify stack trace retrieval
  btrfs: ref-verify: Simplify stack trace retrieval
  dma/debug: Simplify stracktrace retrieval
  fault-inject: Simplify stacktrace retrieval
  mm/page_owner: Simplify stack trace handling
  ...
2019-05-06 13:11:48 -07:00
Linus Torvalds
51987affd6 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:

 - a couple of ->i_link use-after-free fixes

 - regression fix for wrong errno on absent device name in mount(2)
   (this cycle stuff)

 - ancient UFS braino in large GID handling on Solaris UFS images (bogus
   cut'n'paste from large UID handling; wrong field checked to decide
   whether we should look at old (16bit) or new (32bit) field)

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ufs: fix braino in ufs_get_inode_gid() for solaris UFS flavour
  Abort file_remove_privs() for non-reg. files
  [fix] get rid of checking for absent device name in vfs_get_tree()
  apparmorfs: fix use-after-free on symlink traversal
  securityfs: fix use-after-free on symlink traversal
2019-05-05 09:28:45 -07:00
Linus Torvalds
5ce3307b6d for-linus-20190502
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Merge tag 'for-linus-20190502' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "This is mostly io_uring fixes/tweaks. Most of these were actually done
  in time for the last -rc, but I wanted to ensure that everything
  tested out great before including them. The code delta looks larger
  than it really is, as it's mostly just comment additions/changes.

  Outside of the comment additions/changes, this is mostly removal of
  unnecessary barriers. In all, this pull request contains:

   - Tweak to how we handle errors at submission time. We now post a
     completion event if the error occurs on behalf of an sqe, instead
     of returning it through the system call. If the error happens
     outside of a specific sqe, we return the error through the system
     call. This makes it nicer to use and makes the "normal" use case
     behave the same as the offload cases. (me)

   - Fix for a missing req reference drop from async context (me)

   - If an sqe is submitted with RWF_NOWAIT, don't punt it to async
     context. Return -EAGAIN directly, instead of using it as a hint to
     do async punt. (Stefan)

   - Fix notes on barriers (Stefan)

   - Remove unnecessary barriers (Stefan)

   - Fix potential double free of memory in setup error (Mark)

   - Further improve sq poll CPU validation (Mark)

   - Fix page allocation warning and leak on buffer registration error
     (Mark)

   - Fix iov_iter_type() for new no-ref flag (Ming)

   - Fix a case where dio doesn't honor bio no-page-ref (Ming)"

* tag 'for-linus-20190502' of git://git.kernel.dk/linux-block:
  io_uring: avoid page allocation warnings
  iov_iter: fix iov_iter_type
  block: fix handling for BIO_NO_PAGE_REF
  io_uring: drop req submit reference always in async punt
  io_uring: free allocated io_memory once
  io_uring: fix SQPOLL cpu validation
  io_uring: have submission side sqe errors post a cqe
  io_uring: remove unnecessary barrier after unsetting IORING_SQ_NEED_WAKEUP
  io_uring: remove unnecessary barrier after incrementing dropped counter
  io_uring: remove unnecessary barrier before reading SQ tail
  io_uring: remove unnecessary barrier after updating SQ head
  io_uring: remove unnecessary barrier before reading cq head
  io_uring: remove unnecessary barrier before wq_has_sleeper
  io_uring: fix notes on barriers
  io_uring: fix handling SQEs requesting NOWAIT
2019-05-02 09:55:04 -07:00
Al Viro
4e9036042f ufs: fix braino in ufs_get_inode_gid() for solaris UFS flavour
To choose whether to pick the GID from the old (16bit) or new (32bit)
field, we should check if the old gid field is set to 0xffff.  Mainline
checks the old *UID* field instead - cut'n'paste from the corresponding
code in ufs_get_inode_uid().

Fixes: 252e211e90
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-02 02:24:50 -04:00
Linus Torvalds
7e74e235bb gcc-9: don't warn about uninitialized btrfs extent_type variable
The 'extent_type' variable does seem to be reliably initialized, but
it's _very_ non-obvious, since there's a "goto next" case that jumps
over the normal initialization.  That will then always trigger the
"start >= extent_end" test, which will end up never falling through to
the use of that variable.

But the code is certainly not obvious, and the compiler warning looks
reasonable.  Make 'extent_type' an int, and initialize it to an invalid
negative value, which seems to be the common pattern in other places.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-01 12:19:20 -07:00
Mark Rutland
d4ef647510 io_uring: avoid page allocation warnings
In io_sqe_buffer_register() we allocate a number of arrays based on the
iov_len from the user-provided iov. While we limit iov_len to SZ_1G,
we can still attempt to allocate arrays exceeding MAX_ORDER.

On a 64-bit system with 4KiB pages, for an iov where iov_base = 0x10 and
iov_len = SZ_1G, we'll calculate that nr_pages = 262145. When we try to
allocate a corresponding array of (16-byte) bio_vecs, requiring 4194320
bytes, which is greater than 4MiB. This results in SLUB warning that
we're trying to allocate greater than MAX_ORDER, and failing the
allocation.

Avoid this by using kvmalloc() for allocations dependent on the
user-provided iov_len. At the same time, fix a leak of imu->bvec when
registration fails.

Full splat from before this patch:

WARNING: CPU: 1 PID: 2314 at mm/page_alloc.c:4595 __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 2314 Comm: syz-executor326 Not tainted 5.1.0-rc7-dirty #4
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0x0/0x2f0 include/linux/compiler.h:193
 show_stack+0x20/0x30 arch/arm64/kernel/traps.c:158
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x110/0x190 lib/dump_stack.c:113
 panic+0x384/0x68c kernel/panic.c:214
 __warn+0x2bc/0x2c0 kernel/panic.c:571
 report_bug+0x228/0x2d8 lib/bug.c:186
 bug_handler+0xa0/0x1a0 arch/arm64/kernel/traps.c:956
 call_break_hook arch/arm64/kernel/debug-monitors.c:301 [inline]
 brk_handler+0x1d4/0x388 arch/arm64/kernel/debug-monitors.c:316
 do_debug_exception+0x1a0/0x468 arch/arm64/mm/fault.c:831
 el1_dbg+0x18/0x8c
 __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595
 alloc_pages_current+0x164/0x278 mm/mempolicy.c:2132
 alloc_pages include/linux/gfp.h:509 [inline]
 kmalloc_order+0x20/0x50 mm/slab_common.c:1231
 kmalloc_order_trace+0x30/0x2b0 mm/slab_common.c:1243
 kmalloc_large include/linux/slab.h:480 [inline]
 __kmalloc+0x3dc/0x4f0 mm/slub.c:3791
 kmalloc_array include/linux/slab.h:670 [inline]
 io_sqe_buffer_register fs/io_uring.c:2472 [inline]
 __io_uring_register fs/io_uring.c:2962 [inline]
 __do_sys_io_uring_register fs/io_uring.c:3008 [inline]
 __se_sys_io_uring_register fs/io_uring.c:2990 [inline]
 __arm64_sys_io_uring_register+0x9e0/0x1bc8 fs/io_uring.c:2990
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:47 [inline]
 el0_svc_common.constprop.0+0x148/0x2e0 arch/arm64/kernel/syscall.c:83
 el0_svc_handler+0xdc/0x100 arch/arm64/kernel/syscall.c:129
 el0_svc+0x8/0xc arch/arm64/kernel/entry.S:948
SMP: stopping secondary CPUs
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
CPU features: 0x002,23000438
Memory Limit: none
Rebooting in 1 seconds..

Fixes: edafccee56 ("io_uring: add support for pre-mapped user IO buffers")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01 10:00:25 -06:00
Ming Lei
60a27b906d block: fix handling for BIO_NO_PAGE_REF
Commit 399254aaf4 ("block: add BIO_NO_PAGE_REF flag") introduces
BIO_NO_PAGE_REF, and once this flag is set for one bio, all pages
in the bio won't be get/put during IO.

However, if one bio is submitted via __blkdev_direct_IO_simple(),
even though BIO_NO_PAGE_REF is set, pages still may be put.

Fixes this issue by avoiding to put pages if BIO_NO_PAGE_REF is
set.

Fixes: 399254aaf4 ("block: add BIO_NO_PAGE_REF flag")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01 08:38:47 -06:00
Jens Axboe
817869d251 io_uring: drop req submit reference always in async punt
If we don't end up actually calling submit in io_sq_wq_submit_work(),
we still need to drop the submit reference to the request. If we
don't, then we can leak the request. This can happen if we race
with ring shutdown while flushing the workqueue for requests that
require use of the mm_struct.

Fixes: e65ef56db4 ("io_uring: use regular request ref counts")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01 08:38:47 -06:00
Mark Rutland
52e04ef4c9 io_uring: free allocated io_memory once
If io_allocate_scq_urings() fails to allocate an sq_* region, it will
call io_mem_free() for any previously allocated regions, but leave
dangling pointers to these regions in the ctx. Any regions which have
not yet been allocated are left NULL. Note that when returning
-EOVERFLOW, the previously allocated sq_ring is not freed, which appears
to be an unintentional leak.

When io_allocate_scq_urings() fails, io_uring_create() will call
io_ring_ctx_wait_and_kill(), which calls io_mem_free() on all the sq_*
regions, assuming the pointers are valid and not NULL.

This can result in pages being freed multiple times, which has been
observed to corrupt the page state, leading to subsequent fun. This can
also result in virt_to_page() on NULL, resulting in the use of bogus
page addresses, and yet more subsequent fun. The latter can be detected
with CONFIG_DEBUG_VIRTUAL on arm64.

Adding a cleanup path to io_allocate_scq_urings() complicates the logic,
so let's leave it to io_ring_ctx_free() to consistently free these
pointers, and simplify the io_allocate_scq_urings() error paths.

Full splats from before this patch below. Note that the pointer logged
by the DEBUG_VIRTUAL "non-linear address" warning has been hashed, and
is actually NULL.

[   26.098129] page:ffff80000e949a00 count:0 mapcount:-128 mapping:0000000000000000 index:0x0
[   26.102976] flags: 0x63fffc000000()
[   26.104373] raw: 000063fffc000000 ffff80000e86c188 ffff80000ea3df08 0000000000000000
[   26.108917] raw: 0000000000000000 0000000000000001 00000000ffffff7f 0000000000000000
[   26.137235] page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)
[   26.143960] ------------[ cut here ]------------
[   26.146020] kernel BUG at include/linux/mm.h:547!
[   26.147586] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[   26.149163] Modules linked in:
[   26.150287] Process syz-executor.21 (pid: 20204, stack limit = 0x000000000e9cefeb)
[   26.153307] CPU: 2 PID: 20204 Comm: syz-executor.21 Not tainted 5.1.0-rc7-00004-g7d30b2ea43d6 #18
[   26.156566] Hardware name: linux,dummy-virt (DT)
[   26.158089] pstate: 40400005 (nZcv daif +PAN -UAO)
[   26.159869] pc : io_mem_free+0x9c/0xa8
[   26.161436] lr : io_mem_free+0x9c/0xa8
[   26.162720] sp : ffff000013003d60
[   26.164048] x29: ffff000013003d60 x28: ffff800025048040
[   26.165804] x27: 0000000000000000 x26: ffff800025048040
[   26.167352] x25: 00000000000000c0 x24: ffff0000112c2820
[   26.169682] x23: 0000000000000000 x22: 0000000020000080
[   26.171899] x21: ffff80002143b418 x20: ffff80002143b400
[   26.174236] x19: ffff80002143b280 x18: 0000000000000000
[   26.176607] x17: 0000000000000000 x16: 0000000000000000
[   26.178997] x15: 0000000000000000 x14: 0000000000000000
[   26.181508] x13: 00009178a5e077b2 x12: 0000000000000001
[   26.183863] x11: 0000000000000000 x10: 0000000000000980
[   26.186437] x9 : ffff000013003a80 x8 : ffff800025048a20
[   26.189006] x7 : ffff8000250481c0 x6 : ffff80002ffe9118
[   26.191359] x5 : ffff80002ffe9118 x4 : 0000000000000000
[   26.193863] x3 : ffff80002ffefe98 x2 : 44c06ddd107d1f00
[   26.196642] x1 : 0000000000000000 x0 : 000000000000003e
[   26.198892] Call trace:
[   26.199893]  io_mem_free+0x9c/0xa8
[   26.201155]  io_ring_ctx_wait_and_kill+0xec/0x180
[   26.202688]  io_uring_setup+0x6c4/0x6f0
[   26.204091]  __arm64_sys_io_uring_setup+0x18/0x20
[   26.205576]  el0_svc_common.constprop.0+0x7c/0xe8
[   26.207186]  el0_svc_handler+0x28/0x78
[   26.208389]  el0_svc+0x8/0xc
[   26.209408] Code: aa0203e0 d0006861 9133a021 97fcdc3c (d4210000)
[   26.211995] ---[ end trace bdb81cd43a21e50d ]---

[   81.770626] ------------[ cut here ]------------
[   81.825015] virt_to_phys used for non-linear address: 000000000d42f2c7 (          (null))
[   81.827860] WARNING: CPU: 1 PID: 30171 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x48/0x68
[   81.831202] Modules linked in:
[   81.832212] CPU: 1 PID: 30171 Comm: syz-executor.20 Not tainted 5.1.0-rc7-00004-g7d30b2ea43d6 #19
[   81.835616] Hardware name: linux,dummy-virt (DT)
[   81.836863] pstate: 60400005 (nZCv daif +PAN -UAO)
[   81.838727] pc : __virt_to_phys+0x48/0x68
[   81.840572] lr : __virt_to_phys+0x48/0x68
[   81.842264] sp : ffff80002cf67c70
[   81.843858] x29: ffff80002cf67c70 x28: ffff800014358e18
[   81.846463] x27: 0000000000000000 x26: 0000000020000080
[   81.849148] x25: 0000000000000000 x24: ffff80001bb01f40
[   81.851986] x23: ffff200011db06c8 x22: ffff2000127e3c60
[   81.854351] x21: ffff800014358cc0 x20: ffff800014358d98
[   81.856711] x19: 0000000000000000 x18: 0000000000000000
[   81.859132] x17: 0000000000000000 x16: 0000000000000000
[   81.861586] x15: 0000000000000000 x14: 0000000000000000
[   81.863905] x13: 0000000000000000 x12: ffff1000037603e9
[   81.866226] x11: 1ffff000037603e8 x10: 0000000000000980
[   81.868776] x9 : ffff80002cf67840 x8 : ffff80001bb02920
[   81.873272] x7 : ffff1000037603e9 x6 : ffff80001bb01f47
[   81.875266] x5 : ffff1000037603e9 x4 : dfff200000000000
[   81.876875] x3 : ffff200010087528 x2 : ffff1000059ecf58
[   81.878751] x1 : 44c06ddd107d1f00 x0 : 0000000000000000
[   81.880453] Call trace:
[   81.881164]  __virt_to_phys+0x48/0x68
[   81.882919]  io_mem_free+0x18/0x110
[   81.886585]  io_ring_ctx_wait_and_kill+0x13c/0x1f0
[   81.891212]  io_uring_setup+0xa60/0xad0
[   81.892881]  __arm64_sys_io_uring_setup+0x2c/0x38
[   81.894398]  el0_svc_common.constprop.0+0xac/0x150
[   81.896306]  el0_svc_handler+0x34/0x88
[   81.897744]  el0_svc+0x8/0xc
[   81.898715] ---[ end trace b4a703802243cbba ]---

Fixes: 2b188cc1bb ("Add io_uring IO interface")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-block@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01 08:38:47 -06:00
Mark Rutland
975554b03e io_uring: fix SQPOLL cpu validation
In io_sq_offload_start(), we call cpu_possible() on an unbounded cpu
value from userspace. On v5.1-rc7 on arm64 with
CONFIG_DEBUG_PER_CPU_MAPS, this results in a splat:

  WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpu_max_bits_warn include/linux/cpumask.h:121 [inline]

There was an attempt to fix this in commit:

  917257daa0 ("io_uring: only test SQPOLL cpu after we've verified it")

... by adding a check after the cpu value had been limited to NR_CPU_IDS
using array_index_nospec(). However, this left an unbound check at the
start of the function, for which the warning still fires.

Let's fix this correctly by checking that the cpu value is bound by
nr_cpu_ids before passing it to cpu_possible(). Note that only
nr_cpu_ids of a cpumask are guaranteed to exist at runtime, and
nr_cpu_ids can be significantly smaller than NR_CPUs. For example, an
arm64 defconfig has NR_CPUS=256, while my test VM has 4 vCPUs.

Following the intent from the commit message for 917257daa0, the
check is moved under the SQ_AFF branch, which is the only branch where
the cpu values is consumed. The check is performed before bounding the
value with array_index_nospec() so that we don't silently accept bogus
cpu values from userspace, where array_index_nospec() would force these
values to 0.

I suspect we can remove the array_index_nospec() call entirely, but I've
conservatively left that in place, updated to use nr_cpu_ids to match
the prior check.

Tested on arm64 with the Syzkaller reproducer:

  https://syzkaller.appspot.com/bug?extid=cd714a07c6de2bc34293
  https://syzkaller.appspot.com/x/repro.syz?x=15d8b397200000

Full splat from before this patch:

WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpu_max_bits_warn include/linux/cpumask.h:121 [inline]
WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpumask_check include/linux/cpumask.h:128 [inline]
WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 cpumask_test_cpu include/linux/cpumask.h:344 [inline]
WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 io_sq_offload_start fs/io_uring.c:2244 [inline]
WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 io_uring_create fs/io_uring.c:2864 [inline]
WARNING: CPU: 1 PID: 27601 at include/linux/cpumask.h:121 io_uring_setup+0x1108/0x15a0 fs/io_uring.c:2916
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 27601 Comm: syz-executor.0 Not tainted 5.1.0-rc7 #3
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0x0/0x2f0 include/linux/compiler.h:193
 show_stack+0x20/0x30 arch/arm64/kernel/traps.c:158
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x110/0x190 lib/dump_stack.c:113
 panic+0x384/0x68c kernel/panic.c:214
 __warn+0x2bc/0x2c0 kernel/panic.c:571
 report_bug+0x228/0x2d8 lib/bug.c:186
 bug_handler+0xa0/0x1a0 arch/arm64/kernel/traps.c:956
 call_break_hook arch/arm64/kernel/debug-monitors.c:301 [inline]
 brk_handler+0x1d4/0x388 arch/arm64/kernel/debug-monitors.c:316
 do_debug_exception+0x1a0/0x468 arch/arm64/mm/fault.c:831
 el1_dbg+0x18/0x8c
 cpu_max_bits_warn include/linux/cpumask.h:121 [inline]
 cpumask_check include/linux/cpumask.h:128 [inline]
 cpumask_test_cpu include/linux/cpumask.h:344 [inline]
 io_sq_offload_start fs/io_uring.c:2244 [inline]
 io_uring_create fs/io_uring.c:2864 [inline]
 io_uring_setup+0x1108/0x15a0 fs/io_uring.c:2916
 __do_sys_io_uring_setup fs/io_uring.c:2929 [inline]
 __se_sys_io_uring_setup fs/io_uring.c:2926 [inline]
 __arm64_sys_io_uring_setup+0x50/0x70 fs/io_uring.c:2926
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:47 [inline]
 el0_svc_common.constprop.0+0x148/0x2e0 arch/arm64/kernel/syscall.c:83
 el0_svc_handler+0xdc/0x100 arch/arm64/kernel/syscall.c:129
 el0_svc+0x8/0xc arch/arm64/kernel/entry.S:948
SMP: stopping secondary CPUs
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
CPU features: 0x002,23000438
Memory Limit: none
Rebooting in 1 seconds..

Fixes: 917257daa0 ("io_uring: only test SQPOLL cpu after we've verified it")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-block@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Simplied the logic

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01 08:38:37 -06:00
Jens Axboe
5c8b0b54db io_uring: have submission side sqe errors post a cqe
Currently we only post a cqe if we get an error OUTSIDE of submission.
For submission, we return the error directly through io_uring_enter().
This is a bit awkward for applications, and it makes more sense to
always post a cqe with an error, if the error happens on behalf of an
sqe.

This changes submission behavior a bit. io_uring_enter() returns -ERROR
for an error, and > 0 for number of sqes submitted. Before this change,
if you wanted to submit 8 entries and had an error on the 5th entry,
io_uring_enter() would return 4 (for number of entries successfully
submitted) and rewind the sqring. The application would then have to
peek at the sqring and figure out what was wrong with the head sqe, and
then skip it itself. With this change, we'll return 5 since we did
consume 5 sqes, and the last sqe (with the error) will result in a cqe
being posted with the error.

This makes the logic easier to handle in the application, and it cleans
up the submission part.

Suggested-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-01 06:37:55 -06:00
Linus Torvalds
f2bc9c908d Merge tag 'fsnotify_for_v5.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fsnotify fix from Jan Kara:
 "A fix of user trigerable NULL pointer dereference syzbot has recently
  spotted.

  The problem was introduced in this merge window so no CC stable is
  needed"

* tag 'fsnotify_for_v5.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fsnotify: Fix NULL ptr deref in fanotify_get_fsid()
2019-04-30 15:03:00 -07:00
Stefan Bühler
62977281a6 io_uring: remove unnecessary barrier after unsetting IORING_SQ_NEED_WAKEUP
There is no operation to order with afterwards, and removing the flag is
not critical in any way.

There will always be a "race condition" where the application will
trigger IORING_ENTER_SQ_WAKEUP when it isn't actually needed.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 09:40:02 -06:00
Stefan Bühler
b841f19524 io_uring: remove unnecessary barrier after incrementing dropped counter
smp_store_release in io_commit_sqring already orders the store to
dropped before the update to SQ head.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 09:40:02 -06:00
Stefan Bühler
82ab082c0e io_uring: remove unnecessary barrier before reading SQ tail
There is no operation before to order with.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 09:40:02 -06:00
Stefan Bühler
9e4c15a393 io_uring: remove unnecessary barrier after updating SQ head
There is no operation afterwards to order with.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 09:40:02 -06:00
Stefan Bühler
115e12e58d io_uring: remove unnecessary barrier before reading cq head
The memory operations before reading cq head are unrelated and we
don't care about their order.

Document that the control dependency in combination with READ_ONCE and
WRITE_ONCE forms a barrier we need.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 09:40:02 -06:00
Stefan Bühler
4f7067c3fb io_uring: remove unnecessary barrier before wq_has_sleeper
wq_has_sleeper has a full barrier internally. The smp_rmb barrier in
io_uring_poll synchronizes with it.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 09:40:02 -06:00
Stefan Bühler
1e84b97b73 io_uring: fix notes on barriers
The application reading the CQ ring needs a barrier to pair with the
smp_store_release in io_commit_cqring, not the barrier after it.

Also a write barrier *after* writing something (but not *before*
writing anything interesting) doesn't order anything, so an smp_wmb()
after writing SQ tail is not needed.

Additionally consider reading SQ head and writing CQ tail in the notes.

Also add some clarifications how the various other fields in the ring
buffers are used.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 09:40:02 -06:00
Stefan Bühler
8449eedaa1 io_uring: fix handling SQEs requesting NOWAIT
Not all request types set REQ_F_FORCE_NONBLOCK when they needed async
punting; reverse logic instead and set REQ_F_NOWAIT if request mustn't
be punted.

Signed-off-by: Stefan Bühler <source@stbuehler.de>

Merged with my previous patch for this.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 09:40:02 -06:00
Thomas Gleixner
6924f5feba btrfs: ref-verify: Simplify stack trace retrieval
Replace the indirection through struct stack_trace with an invocation of
the storage array based interface.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: dm-devel@redhat.com
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: linux-arch@vger.kernel.org
Link: https://lkml.kernel.org/r/20190425094802.338890064@linutronix.de
2019-04-29 12:37:51 +02:00
Thomas Gleixner
e988e5ec18 proc: Simplify task stack retrieval
Replace the indirection through struct stack_trace with an invocation of
the storage array based interface.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org
Cc: dm-devel@redhat.com
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: linux-arch@vger.kernel.org
Link: https://lkml.kernel.org/r/20190425094801.589304463@linutronix.de
2019-04-29 12:37:48 +02:00
Alexander Lochmann
f69e749a49 Abort file_remove_privs() for non-reg. files
file_remove_privs() might be called for non-regular files, e.g.
blkdev inode. There is no reason to do its job on things
like blkdev inodes, pipes, or cdevs. Hence, abort if
file does not refer to a regular inode.

AV: more to the point, for devices there might be any number of
inodes refering to given device.  Which one to strip the permissions
from, even if that made any sense in the first place?  All of them
will be observed with contents modified, after all.

Found by LockDoc (Alexander Lochmann, Horst Schirmeier and Olaf
Spinczyk)

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Alexander Lochmann <alexander.lochmann@tu-dortmund.de>
Signed-off-by: Horst Schirmeier <horst.schirmeier@tu-dortmund.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-28 21:46:57 -04:00
Al Viro
ee948837d7 [fix] get rid of checking for absent device name in vfs_get_tree()
It has no business being there, it's checked by relevant ->get_tree()
as it is *and* it returns the wrong error for no reason whatsoever.

Fixes: f3a09c9201 "introduce fs_context methods"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-28 21:34:21 -04:00
Jan Kara
b1da6a5187 fsnotify: Fix NULL ptr deref in fanotify_get_fsid()
fanotify_get_fsid() is reading mark->connector->fsid under srcu. It can
happen that it sees mark not fully initialized or mark that is already
detached from the object list. In these cases mark->connector
can be NULL leading to NULL ptr dereference. Fix the problem by
being careful when reading mark->connector and check it for being NULL.
Also use WRITE_ONCE when writing the mark just to prevent compiler from
doing something stupid.

Reported-by: syzbot+15927486a4f1bfcbaf91@syzkaller.appspotmail.com
Fixes: 77115225ac ("fanotify: cache fsid in fsnotify_mark_connector")
Signed-off-by: Jan Kara <jack@suse.cz>
2019-04-28 22:14:50 +02:00
Linus Torvalds
975a0f400f for-linus-20190428
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Merge tag 'for-linus-20190428' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A set of io_uring fixes that should go into this release. In
  particular, this contains:

   - The mutex lock vs ctx ref count fix (me)

   - Removal of a dead variable (me)

   - Two race fixes (Stefan)

   - Ring head/tail condition fix for poll full SQ detection (Stefan)"

* tag 'for-linus-20190428' of git://git.kernel.dk/linux-block:
  io_uring: remove 'state' argument from io_{read,write} path
  io_uring: fix poll full SQ detection
  io_uring: fix race condition when sq threads goes sleeping
  io_uring: fix race condition reading SQ entries
  io_uring: fail io_uring_register(2) on a dying io_uring instance
2019-04-28 10:06:32 -07:00
Linus Torvalds
ce944935ee Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "9 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  fs/proc/proc_sysctl.c: Fix a NULL pointer dereference
  mm/page_alloc.c: fix never set ALLOC_NOFRAGMENT flag
  mm/page_alloc.c: avoid potential NULL pointer dereference
  mm, page_alloc: always use a captured page regardless of compaction result
  mm: do not boost watermarks to avoid fragmentation for the DISCONTIG memory model
  lib/test_vmalloc.c: do not create cpumask_t variable on stack
  lib/Kconfig.debug: fix build error without CONFIG_BLOCK
  zram: pass down the bvec we need to read into in the work struct
  mm/memory_hotplug.c: drop memory device reference after find_memory_block()
2019-04-26 18:15:33 -07:00
Linus Torvalds
e9e1a2e7b4 There tracing fixes:
- Use "nosteal" for ring buffer splice pages
  - Memory leak fix in error path of trace_pid_write()
  - Fix preempt_enable_no_resched() (use preempt_enable()) in ring buffer code
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Merge tag 'trace-v5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Three tracing fixes:

   - Use "nosteal" for ring buffer splice pages

   - Memory leak fix in error path of trace_pid_write()

   - Fix preempt_enable_no_resched() (use preempt_enable()) in ring
     buffer code"

* tag 'trace-v5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  trace: Fix preempt_enable_no_resched() abuse
  tracing: Fix a memory leak by early error exit in trace_pid_write()
  tracing: Fix buffer_ref pipe ops
2019-04-26 11:09:55 -07:00
Linus Torvalds
d0473f978e for-5.1-rc6-tag
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Merge tag 'for-5.1-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "One patch to fix a crash in io submission path, due to memory
  allocation errors.

  In short, the multipage bio work that landed in 5.1 caused larger bios
  that in turn require larger temporary memory for checksums. The patch
  is a workaround, we're going to rework the allocation so it does not
  require the vmalloc fallback.

  It took a while to identify that it's caused by patches in 5.1 and not
  a patchset that did some changes in error handling in the code. I've
  tested it on various memory/cpu combinations, it could hit OOM but
  does not crash.

  The timestamp of the patch is less than a day due to updates in the
  changelog, tests were running meanwhile"

* tag 'for-5.1-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: Switch memory allocations in async csum calculation path to kvmalloc
2019-04-26 09:46:46 -07:00
Linus Torvalds
58130235bf three small SMB3 fixes: 2 leaks and a rename bug
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Merge tag '5.1-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Three small SMB3 fixes (all for stable as well): two leaks and a
  rename bug"

* tag '5.1-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix page reference leak with readv/writev
  cifs: do not attempt cifs operation on smb2+ rename error
  cifs: fix memory leak in SMB2_read
2019-04-26 09:45:39 -07:00
YueHaibing
89189557b4 fs/proc/proc_sysctl.c: Fix a NULL pointer dereference
Syzkaller report this:

  sysctl could not get directory: /net//bridge -12
  kasan: CONFIG_KASAN_INLINE enabled
  kasan: GPF could be caused by NULL-ptr deref or user memory access
  general protection fault: 0000 [#1] SMP KASAN PTI
  CPU: 1 PID: 7027 Comm: syz-executor.0 Tainted: G         C        5.1.0-rc3+ #8
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
  RIP: 0010:__write_once_size include/linux/compiler.h:220 [inline]
  RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:144 [inline]
  RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:186 [inline]
  RIP: 0010:rb_erase+0x5f4/0x19f0 lib/rbtree.c:459
  Code: 00 0f 85 60 13 00 00 48 89 1a 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 75 0c 00 00 4d 85 ed 4c 89 2e 74 ce 4c 89 ea 48
  RSP: 0018:ffff8881bb507778 EFLAGS: 00010206
  RAX: dffffc0000000000 RBX: ffff8881f224b5b8 RCX: ffffffff818f3f6a
  RDX: 000000000000000a RSI: 0000000000000050 RDI: ffff8881f224b568
  RBP: 0000000000000000 R08: ffffed10376a0ef4 R09: ffffed10376a0ef4
  R10: 0000000000000001 R11: ffffed10376a0ef4 R12: ffff8881f224b558
  R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  FS:  00007f3e7ce13700(0000) GS:ffff8881f7300000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fd60fbe9398 CR3: 00000001cb55c001 CR4: 00000000007606e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
   erase_entry fs/proc/proc_sysctl.c:178 [inline]
   erase_header+0xe3/0x160 fs/proc/proc_sysctl.c:207
   start_unregistering fs/proc/proc_sysctl.c:331 [inline]
   drop_sysctl_table+0x558/0x880 fs/proc/proc_sysctl.c:1631
   get_subdir fs/proc/proc_sysctl.c:1022 [inline]
   __register_sysctl_table+0xd65/0x1090 fs/proc/proc_sysctl.c:1335
   br_netfilter_init+0x68/0x1000 [br_netfilter]
   do_one_initcall+0xbc/0x47d init/main.c:901
   do_init_module+0x1b5/0x547 kernel/module.c:3456
   load_module+0x6405/0x8c10 kernel/module.c:3804
   __do_sys_finit_module+0x162/0x190 kernel/module.c:3898
   do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  Modules linked in: br_netfilter(+) backlight comedi(C) hid_sensor_hub max3100 ti_ads8688 udc_core fddi snd_mona leds_gpio rc_streamzap mtd pata_netcell nf_log_common rc_winfast udp_tunnel snd_usbmidi_lib snd_usb_toneport snd_usb_line6 snd_rawmidi snd_seq_device snd_hwdep videobuf2_v4l2 videobuf2_common videodev media videobuf2_vmalloc videobuf2_memops rc_gadmei_rm008z 8250_of smm665 hid_tmff hid_saitek hwmon_vid rc_ati_tv_wonder_hd_600 rc_core pata_pdc202xx_old dn_rtmsg as3722 ad714x_i2c ad714x snd_soc_cs4265 hid_kensington panel_ilitek_ili9322 drm drm_panel_orientation_quirks ipack cdc_phonet usbcore phonet hid_jabra hid extcon_arizona can_dev industrialio_triggered_buffer kfifo_buf industrialio adm1031 i2c_mux_ltc4306 i2c_mux ipmi_msghandler mlxsw_core snd_soc_cs35l34 snd_soc_core snd_pcm_dmaengine snd_pcm snd_timer ac97_bus snd_compress snd soundcore gpio_da9055 uio ecdh_generic mdio_thunder of_mdio fixed_phy libphy mdio_cavium iptable_security iptable_raw iptable_mangle
   iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel hsr veth netdevsim vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun joydev mousedev ppdev tpm kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel ide_pci_generic piix aes_x86_64 crypto_simd cryptd ide_core glue_helper input_leds psmouse intel_agp intel_gtt serio_raw ata_generic i2c_piix4 agpgart pata_acpi parport_pc parport floppy rtc_cmos sch_fq_codel ip_tables x_tables sha1_ssse3 sha1_generic ipv6 [last unloaded: br_netfilter]
  Dumping ftrace buffer:
     (ftrace buffer empty)
  ---[ end trace 68741688d5fbfe85 ]---

commit 23da958803 ("fs/proc/proc_sysctl.c: fix NULL pointer
dereference in put_links") forgot to handle start_unregistering() case,
while header->parent is NULL, it calls erase_header() and as seen in the
above syzkaller call trace, accessing &header->parent->root will trigger
a NULL pointer dereference.

As that commit explained, there is also no need to call
start_unregistering() if header->parent is NULL.

Link: http://lkml.kernel.org/r/20190409153622.28112-1-yuehaibing@huawei.com
Fixes: 23da958803 ("fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links")
Fixes: 0e47c99d7f ("sysctl: Replace root_list with links between sysctl_table_sets")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26 09:18:05 -07:00
Jann Horn
b987222654 tracing: Fix buffer_ref pipe ops
This fixes multiple issues in buffer_pipe_buf_ops:

 - The ->steal() handler must not return zero unless the pipe buffer has
   the only reference to the page. But generic_pipe_buf_steal() assumes
   that every reference to the pipe is tracked by the page's refcount,
   which isn't true for these buffers - buffer_pipe_buf_get(), which
   duplicates a buffer, doesn't touch the page's refcount.
   Fix it by using generic_pipe_buf_nosteal(), which refuses every
   attempted theft. It should be easy to actually support ->steal, but the
   only current users of pipe_buf_steal() are the virtio console and FUSE,
   and they also only use it as an optimization. So it's probably not worth
   the effort.
 - The ->get() and ->release() handlers can be invoked concurrently on pipe
   buffers backed by the same struct buffer_ref. Make them safe against
   concurrency by using refcount_t.
 - The pointers stored in ->private were only zeroed out when the last
   reference to the buffer_ref was dropped. As far as I know, this
   shouldn't be necessary anyway, but if we do it, let's always do it.

Link: http://lkml.kernel.org/r/20190404215925.253531-1-jannh@google.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Fixes: 73a757e631 ("ring-buffer: Return reader page back into existing ring buffer")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-26 11:44:39 -04:00
Linus Torvalds
8113a85f87 dentry name handling fixes from Jeff and a memory leak fix from Zheng.
Both are old issues, marked for stable.
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Merge tag 'ceph-for-5.1-rc7' of git://github.com/ceph/ceph-client

Pull ceph fixes from Ilya Dryomov:
 "dentry name handling fixes from Jeff and a memory leak fix from Zheng.

  Both are old issues, marked for stable"

* tag 'ceph-for-5.1-rc7' of git://github.com/ceph/ceph-client:
  ceph: fix ci->i_head_snapc leak
  ceph: handle the case where a dentry has been renamed on outstanding req
  ceph: ensure d_name stability in ceph_dentry_hash()
  ceph: only use d_name directly when parent is locked
2019-04-25 10:48:50 -07:00
Nikolay Borisov
a3d46aea46 btrfs: Switch memory allocations in async csum calculation path to kvmalloc
Recent multi-page biovec rework allowed creation of bios that can span
large regions - up to 128 megabytes in the case of btrfs. OTOH btrfs'
submission path currently allocates a contiguous array to store the
checksums for every bio submitted. This means we can request up to
(128mb / BTRFS_SECTOR_SIZE) * 4 bytes + 32bytes of memory from kmalloc.
On busy systems with possibly fragmented memory said kmalloc can fail
which will trigger BUG_ON due to improper error handling IO submission
context in btrfs.

Until error handling is improved or bios in btrfs limited to a more
manageable size (e.g. 1m) let's use kvmalloc to fallback to vmalloc for
such large allocations. There is no hard requirement that the memory
allocated for checksums during IO submission has to be contiguous, but
this is a simple fix that does not require several non-contiguous
allocations.

For small writes this is unlikely to have any visible effect since
kmalloc will still satisfy allocation requests as usual. For larger
requests the code will just fallback to vmalloc.

We've performed evaluation on several workload types and there was no
significant difference kmalloc vs kvmalloc.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-25 14:17:38 +02:00
Jérôme Glisse
13f5938d82 cifs: fix page reference leak with readv/writev
CIFS can leak pages reference gotten through GUP (get_user_pages*()
through iov_iter_get_pages()). This happen if cifs_send_async_read()
or cifs_write_from_iter() calls fail from within __cifs_readv() and
__cifs_writev() respectively. This patch move page unreference to
cifs_aio_ctx_release() which will happens on all code paths this is
all simpler to follow for correctness.

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-04-24 12:33:59 -05:00
Frank Sorenson
652727bbe1 cifs: do not attempt cifs operation on smb2+ rename error
A path-based rename returning EBUSY will incorrectly try opening
the file with a cifs (NT Create AndX) operation on an smb2+ mount,
which causes the server to force a session close.

If the mount is smb2+, skip the fallback.

Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-04-24 12:33:59 -05:00
Ronnie Sahlberg
05fd5c2c61 cifs: fix memory leak in SMB2_read
Commit 088aaf17aa introduced a leak where
if SMB2_read() returned an error we would return without freeing the
request buffer.

Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-04-24 12:33:59 -05:00
Linus Torvalds
12a54b150f Fix miscellaneous nfsd bugs, in NFSv4.1 callbacks, NFSv4.1
lock-notification callbacks, NFSv3 readdir encoding, and the
 cache/upcall code.
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Merge tag 'nfsd-5.1-1' of git://linux-nfs.org/~bfields/linux

Pull nfsd bugfixes from Bruce Fields:
 "Fix miscellaneous nfsd bugs, in NFSv4.1 callbacks, NFSv4.1
  lock-notification callbacks, NFSv3 readdir encoding, and the
  cache/upcall code"

* tag 'nfsd-5.1-1' of git://linux-nfs.org/~bfields/linux:
  nfsd: wake blocked file lock waiters before sending callback
  nfsd: wake waiters blocked on file_lock before deleting it
  nfsd: Don't release the callback slot unless it was actually held
  nfsd/nfsd3_proc_readdir: fix buffer count and page pointers
  sunrpc: don't mark uninitialised items as VALID.
2019-04-23 13:40:55 -07:00
Yan, Zheng
37659182bf ceph: fix ci->i_head_snapc leak
We missed two places that i_wrbuffer_ref_head, i_wr_ref, i_dirty_caps
and i_flushing_caps may change. When they are all zeros, we should free
i_head_snapc.

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/38224
Reported-and-tested-by: Luis Henriques <lhenriques@suse.com>
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2019-04-23 21:37:54 +02:00
Jeff Layton
4b82228700 ceph: handle the case where a dentry has been renamed on outstanding req
It's possible for us to issue a lookup to revalidate a dentry
concurrently with a rename. If done in the right order, then we could
end up processing dentry info in the reply that no longer reflects the
state of the dentry.

If req->r_dentry->d_name differs from the one in the trace, then just
ignore the trace in the reply. We only need to do this however if the
parent's i_rwsem is not held.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2019-04-23 21:37:54 +02:00
Jeff Layton
76a495d666 ceph: ensure d_name stability in ceph_dentry_hash()
Take the d_lock here to ensure that d_name doesn't change.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2019-04-23 21:37:54 +02:00
Jeff Layton
1bcb344086 ceph: only use d_name directly when parent is locked
Ben reported tripping the BUG_ON in create_request_message during some
performance testing. Analysis of the vmcore showed that the length of
the r_dentry->d_name string changed after we allocated the buffer, but
before we encoded it.

build_dentry_path returns pointers to d_name in the common case of
non-snapped dentries, but this optimization isn't safe unless the parent
directory is locked. When it isn't, have the code make a copy of the
d_name while holding the d_lock.

Cc: stable@vger.kernel.org
Reported-by: Ben England <bengland@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2019-04-23 21:37:54 +02:00
Jens Axboe
8358e3a826 io_uring: remove 'state' argument from io_{read,write} path
Since commit 09bb839434 we don't use the state argument for any sort
of on-stack caching in the io read and write path. Remove the stale
and unused argument from them, and bubble it up to __io_submit_sqe()
and down to io_prep_rw().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-23 08:17:58 -06:00
Jeff Layton
f456458e4d nfsd: wake blocked file lock waiters before sending callback
When a blocked NFS lock is "awoken" we send a callback to the server and
then wake any hosts waiting on it. If a client attempts to get a lock
and then drops off the net, we could end up waiting for a long time
until we end up waking locks blocked on that request.

So, wake any other waiting lock requests before sending the callback.
Do this by calling locks_delete_block in a new "prepare" phase for
CB_NOTIFY_LOCK callbacks.

URL: https://bugzilla.kernel.org/show_bug.cgi?id=203363
Fixes: 16306a61d3 ("fs/locks: always delete_block after waiting.")
Reported-by: Slawomir Pryczek <slawek1211@gmail.com>
Cc: Neil Brown <neilb@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-22 15:38:41 -04:00
Jeff Layton
6aaafc43a4 nfsd: wake waiters blocked on file_lock before deleting it
After a blocked nfsd file_lock request is deleted, knfsd will send a
callback to the client and then free the request. Commit 16306a61d3
("fs/locks: always delete_block after waiting.") changed it such that
locks_delete_block is always called on a request after it is awoken,
but that patch missed fixing up blocked nfsd request handling.

Call locks_delete_block on the block to wake up any locks still blocked
on the nfsd lock request before freeing it. Some of its callers already
do this however, so just remove those calls.

URL: https://bugzilla.kernel.org/show_bug.cgi?id=203363
Fixes: 16306a61d3 ("fs/locks: always delete_block after waiting.")
Reported-by: Slawomir Pryczek <slawek1211@gmail.com>
Cc: Neil Brown <neilb@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-22 15:31:54 -04:00
Stefan Bühler
fb775faa9e io_uring: fix poll full SQ detection
io_uring_poll shouldn't signal EPOLLOUT | EPOLLWRNORM if the queue is
full; the old check would always signal EPOLLOUT | EPOLLWRNORM (unless
there were U32_MAX - 1 entries in the SQ queue).

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22 11:00:58 -06:00
Stefan Bühler
0d7bae69c5 io_uring: fix race condition when sq threads goes sleeping
Reading the SQ tail needs to come after setting IORING_SQ_NEED_WAKEUP in
flags; there is no cheap barrier for ordering a store before a load, a
full memory barrier is required.

Userspace needs a full memory barrier between updating SQ tail and
checking for the IORING_SQ_NEED_WAKEUP too.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22 11:00:56 -06:00
Stefan Bühler
e523a29c4f io_uring: fix race condition reading SQ entries
A read memory barrier is required between reading SQ tail and reading
the actual data belonging to the SQ entry.

Userspace needs a matching write barrier between writing SQ entries and
updating SQ tail (using smp_store_release to update tail will do).

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22 11:00:55 -06:00
Jens Axboe
35fa71a030 io_uring: fail io_uring_register(2) on a dying io_uring instance
If we have multiple threads doing io_uring_register(2) on an io_uring
fd, then we can potentially try and kill the percpu reference while
someone else has already killed it.

Prevent this race by failing io_uring_register(2) if the ref is marked
dying. This is safe since we're inside the io_uring mutex.

Fixes: b19062a567 ("io_uring: fix possible deadlock between io_uring_{enter,register}")
Reported-by: syzbot <syzbot+10d25e23199614b7721f@syzkaller.appspotmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22 10:37:07 -06:00
Linus Torvalds
38a2ca2cac for-linus-20190420
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Merge tag 'for-linus-20190420' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A set of small fixes that should go into this series. This contains:

   - Removal of unused queue member (Hou)

   - Overflow bvec fix (Ming)

   - Various little io_uring tweaks (me)
       - kthread parking
       - Only call cpu_possible() for verified CPU
       - Drop unused 'file' argument to io_file_put()
       - io_uring_enter vs io_uring_register deadlock fix
       - CQ overflow fix

   - BFQ internal depth update fix (me)"

* tag 'for-linus-20190420' of git://git.kernel.dk/linux-block:
  block: make sure that bvec length can't be overflow
  block: kill all_q_node in request_queue
  io_uring: fix CQ overflow condition
  io_uring: fix possible deadlock between io_uring_{enter,register}
  io_uring: drop io_file_put() 'file' argument
  bfq: update internal depth state when queue depth changes
  io_uring: only test SQPOLL cpu after we've verified it
  io_uring: park SQPOLL thread if it's percpu
2019-04-20 12:20:58 -07:00