| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
sched_ext: Don't run ops.dequeue() with a DSQ lock held
ops.dequeue() is invoked with the source user DSQ's lock still held on
the consume and move paths (scx_consume_dispatch_q(),
move_task_between_dsqs()). A BPF scheduler which locks the source user
DSQ from ops.dequeue() - e.g. by iterating it with bpf_iter_scx_dsq -
self-deadlocks.
ops.dequeue() can only call the "any" kfuncs and none of them can lock a
builtin DSQ, so the global and bypass paths can't deadlock; however,
all DSQ locks share one lockdep class, so iterating any user DSQ from
ops.dequeue() on those paths trips the recursion check.
Move the invocation after the DSQ unlock on all three paths.
SCX_TASK_IN_CUSTODY is cleared under the lock serializing the transfer
so that the callback is invoked exactly once. |
| Deadlock in Windows Routing and Remote Access Service (RRAS) allows an unauthorized attacker to deny service over a network. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/slab: do not wake up kswapd in __kfree_rcu_sheaf()
Since kfree_rcu() can be called under pi_lock (a raw spinlock in the
scheduler), kfree_rcu() itself should never allocate memory with
__GFP_KSWAPD_RECLAIM as waking up kswapd ends up acquiring pi_lock,
which leads to a deadlock.
Reproducing the issue even intentionally was not straightforward.
The set_cpus_allowed_force() path that is called under pi_lock is
exercised very rarely, and competing tasks that allocate memory will
most likely wake kswapd up.
Therefore the existence of the deadlock was verified with a modified
kernel that has a lockdep map for waking up kswapd:
======================================================
WARNING: possible circular locking dependency detected
7.2.0-rc1-slab-for-next+ #10 Not tainted
------------------------------------------------------
git/6660 is trying to acquire lock:
ffff8e524533c550 (&p->pi_lock){-.-.}-{2:2}, at: _raw_spin_lock_irqsave+0x12/0x20
but task is already holding lock:
ffff8e57bffff1a0 (&pgdat->kswapd_wait){....}-{3:3}, at: _raw_spin_lock_irqsave+0x12/0x20
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&pgdat->kswapd_wait){....}-{3:3}:
__lock_acquire+0x5a4/0xc50
lock_acquire.part.0+0xb7/0x240
lock_acquire+0x70/0x170
__raw_spin_lock_irqsave+0x44/0x80
_raw_spin_lock_irqsave+0x12/0x20
__wake_up_common_lock+0x31/0xa0
__wake_up+0x20/0x40
kswapd_wakeup_wake+0x7e/0x110
wakeup_kswapd+0x295/0x320
wake_all_kswapds+0xac/0x1a0
__alloc_pages_slowpath.constprop.0+0x282/0xf80
__alloc_frozen_pages_noprof+0x32a/0x360
alloc_slab_page+0x2e/0x160
allocate_slab+0x82/0x420
new_slab+0x52/0xb0
refill_objects+0x13d/0x190
refill_sheaf+0x5d/0xd0
__pcs_replace_empty_main+0x230/0xb10
[...]
-> #1 (kswapd_wakeup){-.-.}-{0:0}:
__lock_acquire+0x5a4/0xc50
lock_sync.part.0+0x75/0x100
lock_sync+0x36/0x70
might_wakeup_kswapd+0x61/0xa0
__kfree_rcu_sheaf+0x33/0xd90
kvfree_call_rcu+0x1d4/0x3b0
set_cpus_allowed_force+0x163/0x220
cpuset_cpus_allowed_fallback+0x18b/0x240
select_fallback_rq+0x1e6/0x250
[...]
-> #0 (&p->pi_lock){-.-.}-{2:2}:
check_prev_add+0xe6/0xe00
validate_chain+0x51e/0x6e0
__lock_acquire+0x5a4/0xc50
lock_acquire.part.0+0xb7/0x240
lock_acquire+0x70/0x170
__raw_spin_lock_irqsave+0x44/0x80
_raw_spin_lock_irqsave+0x12/0x20
try_to_wake_up+0x77/0xa90
default_wake_function+0x27/0x60
autoremove_wake_function+0x23/0xb0
__wake_up_common+0xb8/0x170
__wake_up_common_lock+0x51/0xa0
__wake_up+0x20/0x40
kswapd_wakeup_wake+0x7e/0x110
wakeup_kswapd+0x295/0x320
wake_all_kswapds+0xac/0x1a0
__alloc_pages_slowpath.constprop.0+0x282/0xf80
__alloc_frozen_pages_noprof+0x32a/0x360
alloc_slab_page+0x2e/0x160
allocate_slab+0x82/0x420
new_slab+0x52/0xb0
refill_objects+0x13d/0x190
refill_sheaf+0x5d/0xd0
__pcs_replace_empty_main+0x230/0xb10
[...]
other info that might help us debug this:
Chain exists of:
&p->pi_lock --> kswapd_wakeup --> &pgdat->kswapd_wait
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&pgdat->kswapd_wait);
lock(kswapd_wakeup);
lock(&pgdat->kswapd_wait);
lock(&p->pi_lock);
*** DEADLOCK ***
3 locks held by git/6660:
#0: ffff8e519f0e9e20 (&type->i_mutex_dir_key#6){++++}-{4:4}, at: lookup_slow+0x2d/0x60
#1: ffffffff8a31c460 (kswapd_wakeup){-.-.}-
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
blk-cgroup: save IRQ state in blkg_tryget_closest()
bio_set_dev() associates the bio with a blkg through bio_associate_blkg().
If the blkg lookup misses, blkg_tryget_closest() takes q->queue_lock with
spin_lock_irq() and releases it with spin_unlock_irq(), which
unconditionally enables local interrupts.
Callers may call bio_set_dev() with interrupts already disabled, e.g.
dm-thin's pool_map() does so while holding pool->lock taken with
spin_lock_irq(). The nested spin_unlock_irq() then enables interrupts
while pool->lock is still held, so an I/O completion softirq can run on
the same CPU, re-acquire pool->lock (thin_endio(), or overwrite_endio()
-> complete_mapping_preparation()) and deadlock. lockdep reports this
as inconsistent SOFTIRQ-ON-W to IN-SOFTIRQ-W usage.
Commit 3a762de55b4e ("block: save irq state in blkg_lookup_create()")
fixed the same problem while the lock lived in blkg_lookup_create(), but
commit 9327a865e395 ("blk-cgroup: don't nest queue_lock under rcu in
blkg_lookup_create()") moved the locking into blkg_tryget_closest() and
reverted it to spin_lock_irq().
Save and restore the caller's IRQ state instead. |
| Improper synchronization in the OpenVPN ovpn-dco-win for Windows versions 0.6.5 through 1.3.5 and 2.4.0 through 2.8.7 allows local attackers to trigger a deadlock via a crafted write to the ovpn-dco device, causing the host to become unresponsive. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Keep internal commands dispatchable during error handling
Commit 08b12cda6c44 ("scsi: ufs: core: Switch to scsi_get_internal_cmd()")
switched UFS internal commands to allocate requests on
hba->host->pseudo_sdev->request_queue, which shares the host tagset with
regular LUNs.
During error recovery, ufshcd_err_handling_prepare() calls
blk_mq_quiesce_tagset(&hba->host->tag_set), marking all queues in the
tagset as quiesced, including pseudo_sdev->request_queue. When
ufshcd_verify_dev_init() subsequently issues internal commands (e.g. NOP
OUT UPIU) via blk_execute_rq(), blk_mq_run_hw_queue() skips running the
quiesced queue, resulting in an unrecoverable circular wait deadlock.
Keep quiescing the tagset and unquiesce the pseudo SCSI device on top of
that, so internal commands stay dispatchable while the logical units remain
quiesced. Re-quiesce the pseudo device before unquiescing the tagset so
that quiesce_depth stays balanced.
Clock scaling and ufshcd_pause_command_processing() are unaffected: they
keep quiescing the whole tagset, internal commands included. |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid1,raid10: fix error-path detection with md_cloned_bio()
Detect the error path using md_cloned_bio() instead of relying
on r1_bio in raid1 or r10_bio->read_slot in raid10, which may be
NULL or -1 after splitting and resubmitting a failed bio.
As a result, the error path may not be recognized and memory
allocations can incorrectly use GFP_NOIO instead of
(GFP_NOIO | __GFP_HIGH), which can lead to a deadlock under
memory pressure. |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid5: avoid R5_Overlap races while breaking stripe batches
KCSAN report a race in break_stripe_batch_list() vs. raid5_make_request()
on sh->dev[i].flags (plain word write vs. atomic bit op)..
and .. one possible scenario is:
CPU1 CPU2
break_stripe_batch_list(sh1)
-> handle sh2
-> lock(sh2)
-> sh2->batch_head = NULL
-> unlock(sh2)
-> test_and_clear_bit(R5_Overlap, sh2->dev[i].flags)
-> wake_up_bit(sh2->dev[i].flags)
raid5_make_request()
-> add_all_stripe_bios(sh2)
-> lock(sh2)
-> stripe_bio_overlaps(sh2) returns true
batch_head is NULL, so new bio overlap
exist bio on sh2 -> true
-> set_bit(R5_Overlap, sh2->dev[i].flags)
-> unlock(sh2)
-> wait_on_bit(sh2->dev[i].flags)
-> sh2->dev[i].flags = sh1->dev[i].flags & ~R5_Overlap
No wait_up_bit(), CPU2 could be wait_on_bit() forever...
Fix by :
- Expand the protect zone.
- Use batch_head's device flag's snaphot when no held head_sh->stripe_lock.
- Move sh/head_sh->batch_head = NULL to the end of protected zone , and ,
any concurrent add_all_stripe_bios() grabs sh->stripe_lock now either:
- see batch_head != null, and , is rejected by stripe_bio_overlaps()
under the lock (no R5_Overlap wait ) , or ,
- sees batch_head == NULL, only after dev[i].flags has already been
set and the prior R5_Overlap waiters worken.
KCSAN report:
================================================
BUG: KCSAN: data-race in break_stripe_batch_list / raid5_make_request
write (marked) to 0xffff8e89c8117548 of 8 bytes by task 4042 on cpu 0:
raid5_make_request+0xea0/0x2930
md_handle_request+0x4a2/0xa40
md_submit_bio+0x109/0x1a0
__submit_bio+0x2ec/0x390
submit_bio_noacct_nocheck+0x457/0x710
submit_bio_noacct+0x2a7/0xc20
submit_bio+0x56/0x250
blkdev_direct_IO+0x54c/0xda0
blkdev_write_iter+0x38f/0x570
aio_write+0x22b/0x490
io_submit_one+0xa51/0xf70
__x64_sys_io_submit+0xf7/0x220
x64_sys_call+0x1907/0x1c60
do_syscall_64+0x130/0x570
entry_SYSCALL_64_after_hwframe+0x76/0x7e
read to 0xffff8e89c8117548 of 8 bytes by task 4010 on cpu 5:
break_stripe_batch_list+0x249/0x480
handle_stripe_clean_event+0x720/0x9b0
handle_stripe+0x32fb/0x4500
handle_active_stripes.isra.0+0x6e0/0xa50
raid5d+0x7e0/0xba0
md_thread+0x15a/0x2d0
kthread+0x1e3/0x220
ret_from_fork+0x37a/0x410
ret_from_fork_asm+0x1a/0x30
value changed: 0x0000000000000019 -> 0x0000000000000099 --> R5_Overlap |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/erdma: Use IRQ-safe XArray helpers for QP and CQ tables
Locked QP and CQ lookups from EQ interrupts can deadlock with
create-path XArray updates. If an interrupt arrives while the create
path holds the plain xa_lock, the lookup spins forever trying to
acquire the same lock.
Use IRQ-safe XArray helpers for all QP and CQ create-path updates,
including the GSI QP store and error paths. Initialize both arrays with
XA_FLAGS_LOCK_IRQ so sleeping allocations preserve interrupt state. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/rw: end write accounting from ->ki_complete
Commit b000145e9907 moved both the fsnotify calls and the write
accounting out of the kiocb completion handler and into the
io_req_rw_complete() task_work. However, only the fsnotify part actually
needed to move as it may sleep. Ending the write accounting is just a
percpu_up_read() on the superblock writers sem.
Deferring it is a problem, because it makes dropping SB_FREEZE_WRITE
protection depend on the ring owner getting to running task_work. But
the task may be blocked in freeze_super(), causing it to never get to
that:
task io-wq worker
--------------------------------------------------------------
io_write()
io_kiocb_start_write() (takes sb_writers, hidden from
lockdep by __sb_writers_release)
write_iter() -> -EIOCBQUEUED
ioctl(FS_IOC_SHUTDOWN)
bdev_freeze()
freeze_super()
percpu_down_write() <- waits for the reader above
io_write()
kiocb_start_write()
percpu_down_read() <- queued
behind the
writer
<bio completes>
io_complete_rw()
queues io_req_rw_complete() <- never runs, task is in D state
End the write from io_complete_rw() instead, and leave only the fsnotify
calls in task_work. |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid1,raid10: fix deadlock in read error recovery path
raid1d and raid10d may resubmit a split md cloned bio while handling
a read error. In this case, resubmitting the bio can lead to a deadlock
if the array is suspended before md_handle_request() acquires an
active_io reference via percpu_ref_tryget_live().
Since the cloned bio already holds an active_io reference,
trying to acquire another reference via percpu_ref_tryget_live()
can lead to a deadlock while the array is suspended.
Fix this by using percpu_ref_get() for md cloned bios. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix deadlock cloning inline extent when using flushoncommit
In commit b48c980b6a7e ("btrfs: fix deadlock between reflink and
transaction commit when using flushoncommit") a deadlock was fixed
between reflinks and transaction commits when the fs is mounted with the
flushoncommit option. This happened when we had to copy an inline extent's
data to the destination file. However the issue was fixed only for the
case where the destination offset is 0, it missed the case when the offset
is greater than zero.
Fix this by ensuring we get i_size update whenever we copied an inline
extent's data into the destination file.
Syzbot reported this with the following trace:
INFO: task kworker/u8:3:57 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3 state:D stack:21600 pid:57 tgid:57 ppid:2 task_flags:0x4208160 flags:0x00080000
Workqueue: writeback wb_workfn (flush-btrfs-129)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7298
wait_extent_bit fs/btrfs/extent-io-tree.c:905 [inline]
btrfs_lock_extent_bits+0x59c/0x700 fs/btrfs/extent-io-tree.c:2008
btrfs_lock_extent fs/btrfs/extent-io-tree.h:152 [inline]
btrfs_invalidate_folio+0x440/0xc00 fs/btrfs/inode.c:7718
extent_writepage fs/btrfs/extent_io.c:1848 [inline]
extent_write_cache_pages fs/btrfs/extent_io.c:2552 [inline]
btrfs_writepages+0x12f3/0x2410 fs/btrfs/extent_io.c:2684
do_writepages+0x32e/0x550 mm/page-writeback.c:2571
__writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056
wb_writeback+0x445/0xb00 fs/fs-writeback.c:2241
wb_do_writeback fs/fs-writeback.c:2388 [inline]
wb_workfn+0x3fd/0xf20 fs/fs-writeback.c:2428
process_one_work+0x98b/0x1630 kernel/workqueue.c:3318
process_scheduled_works kernel/workqueue.c:3401 [inline]
worker_thread+0xb49/0x1140 kernel/workqueue.c:3482
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
INFO: task syz.0.145:8523 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.145 state:D stack:22752 pid:8523 tgid:8522 ppid:5850 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7298
wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
__writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2847
try_to_writeback_inodes_sb+0x9a/0xc0 fs/fs-writeback.c:2895
btrfs_start_delalloc_flush fs/btrfs/transaction.c:2182 [inline]
btrfs_commit_transaction+0x813/0x2fc0 fs/btrfs/transaction.c:2371
btrfs_sync_file+0xdf4/0x1230 fs/btrfs/file.c:1822
generic_write_sync include/linux/fs.h:2663 [inline]
btrfs_do_write_iter+0x6a9/0x840 fs/btrfs/file.c:1473
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x629/0xba0 fs/read_write.c:688
ksys_write+0x156/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a0bdece59
RSP: 002b:00007f5a0b446028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5a0c065fa0 RCX: 00007f5a0bdece59
RDX: 000000000000029f RSI: 0000200000
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: validate donor file superblock early in EXT4_IOC_MOVE_EXT
Reject the EXT4_IOC_MOVE_EXT ioctl early if the donor file does not
belong to the same superblock as the original file. Currently, this
validation is performed inside ext4_move_extents() by
mext_check_validity(), but only after lock_two_nondirectories() has
already acquired the inode locks. When the donor fd refers to a file
on a different filesystem (e.g., overlayfs), this late validation
creates a circular lock dependency:
CPU0 (overlayfs write) CPU1 (ext4 ioctl)
---- ----
inode_lock(ovl_inode)
mnt_want_write_file(filp)
sb_start_write(ext4_sb) [sb_writers]
backing_file_write_iter()
vfs_iter_write(real_file)
file_start_write(real_file)
sb_start_write(ext4_sb) [blocked by freeze]
lock_two_nondirectories()
inode_lock(ovl_inode) [blocked]
With a concurrent freeze operation holding sb_writers write side, this
forms a deadlock cycle: CPU0 waits for freeze to complete, freeze waits
for CPU1's sb_writers reader to exit, CPU1 waits for CPU0's inode lock.
Since EXT4_IOC_MOVE_EXT exchanges physical extents between two files,
it fundamentally requires both files to reside on the same ext4
filesystem. Moving the superblock check before any lock acquisition
is both semantically correct and eliminates the circular dependency
by ensuring that cross-filesystem donor fds are rejected before
sb_writers or inode locks are taken. |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs: skip extent mft records in writeback to prevent deadlock
This patch fixes the ABBA deadlock between extent_lock and extent
mrec_lock triggered by xfstests generic/113, that occurs since the commit
6994acf33bae ("ntfs: use base mft_no when looking up base inode for
extent record").
Path A (inode writeback):
VFS writeback
-> ntfs_write_inode()
-> __ntfs_write_inode()
-> mutex_lock(&ni->extent_lock)
-> mutex_lock(&tni->mrec_lock)
Path B (MFT folio writeback):
VFS writeback of $MFT dirty folios
-> ntfs_mft_writepages()
-> ntfs_write_mft_block()
-> ntfs_may_write_mft_record()
-> holds one extent mrec_lock from a previous iteration
-> tries to acquire another base inode extent_lock
By removing all extent_lock and extent mrec_lock acquisition from the MFT
folio writeback path, the ABBA lock ordering is eliminated:
Path A: __ntfs_write_inode(): extent_lock -> mrec_lock
Path B (removed): ntfs_write_mft_block(): mrec_lock -> extent_lock
Path B is always redundant for extent records because:
1. mark_mft_record_dirty(ext_ni) does NOT dirty the MFT folio.
It only sets NInoDirty(ext_ni) and marks the base VFS inode dirty
via __mark_inode_dirty(I_DIRTY_DATASYNC), which triggers Path A.
Therefore, normal extent modifications never create a situation where
the MFT folio is dirty and Path B is not scheduled.
2. The MFT folio only gets dirtied via ntfs_mft_mark_dirty() inside
ntfs_mft_record_alloc(). But all identified callers in attrib.c
(ntfs_attr_add, ntfs_attr_record_move_away,
ntfs_attr_make_non_resident, ntfs_attr_record_resize) follow through
with mark_mft_record_dirty(), which triggers Path A to write the
complete record.
3. ntfs_evict_big_inode() calls ntfs_commit_inode() before freeing extent
inodes, ensuring all dirty extents are flushed via Path A before the
base inode leaves the icache. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: convert pmsr_free_wk to wiphy_work to fix deadlock
When a netlink socket that owns a PMSR session is closed,
cfg80211_release_pmsr() clears the request's nl_portid and queues
pmsr_free_wk to call cfg80211_pmsr_process_abort() asynchronously.
If the interface tears down concurrently, cfg80211_pmsr_wdev_down()
is called under wiphy_lock and calls cancel_work_sync(&pmsr_free_wk)
to wait for any running work. The work function acquires wiphy_lock
via guard(wiphy) before calling process_abort.
This is a deadlock: wdev_down holds wiphy_lock and blocks inside
cancel_work_sync(); pmsr_free_wk blocks trying to acquire that same
wiphy_lock. Neither thread can proceed.
The same deadlock is reachable from cfg80211_leave_locked(), which
calls cfg80211_pmsr_wdev_down() for all interface types under
wiphy_lock.
Fix this by converting pmsr_free_wk from a plain work_struct to a
wiphy_work. The wiphy_work dispatcher holds wiphy_lock when running
work items, so the explicit guard(wiphy) in the work function is no
longer needed. wiphy_work_cancel() can be called safely while holding
wiphy_lock - since wiphy_lock prevents the work from running
concurrently, wiphy_work_cancel() never blocks, eliminating the
deadlock.
Remove the cancel_work_sync() for pmsr_free_wk from the
NETDEV_GOING_DOWN handler. cfg80211_leave(), called unconditionally
just before it, already cancels any pending work under wiphy_lock
via wiphy_work_cancel() inside cfg80211_pmsr_wdev_down(). |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7925: fix potential deadlock in mt7925_roc_abort_sync
roc_abort_sync() can deadlock with roc_work(). roc_work() holds
dev->mt76.mutex, while cancel_work_sync() waits for roc_work()
to finish. If the caller already owns the same mutex, both
sides block and no progress is possible.
This deadlock can occur during station removal when
mt76_sta_state() -> mt76_sta_remove() ->
mt7925_mac_sta_remove_link() -> mt7925_mac_link_sta_remove() ->
mt7925_roc_abort_sync() invokes cancel_work_sync() while
roc_work() is still running and holding dev->mt76.mutex.
This avoids the mutex deadlock and preserves exactly-once
work ownership. |
| In the Linux kernel, the following vulnerability has been resolved:
NFS/localio: prevent direct reclaim recursion into NFS via nfs_writepages
LOCALIO is an NFS loopback mount optimization that avoids using the
network for READ, WRITE and COMMIT if the NFS client and server are
determined to be on the same system. But because LOCALIO is still
fundamentally "just NFS loopback mount" it is susceptible to recursion
deadlock via direct reclaim, e.g.: NFS LOCALIO down to XFS and then
back into NFS via nfs_writepages.
Fix LOCALIO's potential for direct reclaim deadlock by ensuring that
all its page cache allocations are done from GFP_NOFS context.
Thanks to Ben Coddington for pointing out commit ad22c7a043c2 ("xfs:
prevent stack overflows from page cache allocation"). |
| In the Linux kernel, the following vulnerability has been resolved:
mm/damon/core: fix damos_walk() vs kdamond_fn() exit race
When kdamond_fn() main loop is finished, the function cancels remaining
damos_walk() request and unset the damon_ctx->kdamond so that API callers
and API functions themselves can show the context is terminated.
damos_walk() adds the caller's request to the queue first. After that, it
shows if the kdamond of the damon_ctx is still running (damon_ctx->kdamond
is set). Only if the kdamond is running, damos_walk() starts waiting for
the kdamond's handling of the newly added request.
The damos_walk() requests registration and damon_ctx->kdamond unset are
protected by different mutexes, though. Hence, damos_walk() could race
with damon_ctx->kdamond unset, and result in deadlocks.
For example, let's suppose kdamond successfully finished the damow_walk()
request cancelling. Right after that, damos_walk() is called for the
context. It registers the new request, and shows the context is still
running, because damon_ctx->kdamond unset is not yet done. Hence the
damos_walk() caller starts waiting for the handling of the request.
However, the kdamond is already on the termination steps, so it never
handles the new request. As a result, the damos_walk() caller thread
infinitely waits.
Fix this by introducing another damon_ctx field, namely
walk_control_obsolete. It is protected by the
damon_ctx->walk_control_lock, which protects damos_walk() request
registration. Initialize (unset) it in kdamond_fn() before letting
damon_start() returns and set it just before the cancelling of the
remaining damos_walk() request is executed. damos_walk() reads the
obsolete field under the lock and avoids adding a new request.
After this change, only requests that are guaranteed to be handled or
cancelled are registered. Hence the after-registration DAMON context
termination check is no longer needed. Remove it together.
The issue is found by sashiko [1]. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/mlx5: Fix UMR hang in LAG error state unload
During firmware reset in LAG mode, a race condition causes the driver
to hang indefinitely while waiting for UMR completion during device
unload. See [1].
In LAG mode the bond device is only registered on the master, so it
never sees sys_error events from the slave.
During firmware reset this causes UMR waits to hang forever on unload
as the slave is dead but the master hasn't entered error state yet, so
UMR posts succeed but completions never arrive.
Fix this by adding a sys_error notifier that gets registered before
MLX5_IB_STAGE_IB_REG and stays alive until after ib_unregister_device().
This ensures error events reach the bond device throughout teardown.
[1]
Call Trace:
__schedule+0x2bd/0x760
schedule+0x37/0xa0
schedule_preempt_disabled+0xa/0x10
__mutex_lock.isra.6+0x2b5/0x4a0
__mlx5_ib_dereg_mr+0x606/0x870 [mlx5_ib]
? __xa_erase+0x4a/0xa0
? _cond_resched+0x15/0x30
? wait_for_completion+0x31/0x100
ib_dereg_mr_user+0x48/0xc0 [ib_core]
? rdmacg_uncharge_hierarchy+0xa0/0x100
destroy_hw_idr_uobject+0x20/0x50 [ib_uverbs]
uverbs_destroy_uobject+0x37/0x150 [ib_uverbs]
__uverbs_cleanup_ufile+0xda/0x140 [ib_uverbs]
uverbs_destroy_ufile_hw+0x3a/0xf0 [ib_uverbs]
ib_uverbs_remove_one+0xc3/0x140 [ib_uverbs]
remove_client_context+0x8b/0xd0 [ib_core]
disable_device+0x8c/0x130 [ib_core]
__ib_unregister_device+0x10d/0x180 [ib_core]
ib_unregister_device+0x21/0x30 [ib_core]
__mlx5_ib_remove+0x1e4/0x1f0 [mlx5_ib]
auxiliary_bus_remove+0x1e/0x30
device_release_driver_internal+0x103/0x1f0
bus_remove_device+0xf7/0x170
device_del+0x181/0x410
mlx5_rescan_drivers_locked.part.10+0xa9/0x1d0 [mlx5_core]
mlx5_disable_lag+0x253/0x260 [mlx5_core]
mlx5_lag_disable_change+0x89/0xc0 [mlx5_core]
mlx5_eswitch_disable+0x67/0xa0 [mlx5_core]
mlx5_unload+0x15/0xd0 [mlx5_core]
mlx5_unload_one+0x71/0xc0 [mlx5_core]
mlx5_sync_reset_reload_work+0x83/0x100 [mlx5_core]
process_one_work+0x1a7/0x360
worker_thread+0x30/0x390
? create_worker+0x1a0/0x1a0
kthread+0x116/0x130
? kthread_flush_work_fn+0x10/0x10
ret_from_fork+0x22/0x40 |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: revert commit_mutex usage in reset path
It causes circular lock dependency between commit_mutex, nfnl_subsys_ipset
and nlk_cb_mutex when nft reset, ipset list, and iptables-nft with '-m set'
rule run at the same time.
Previous patches made it safe to run individual reset handlers concurrently
so commit_mutex is no longer required to prevent this. |
