| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: avoid holding freeze_mutex during mmap operation
We use map->freeze_mutex to prevent races between map_freeze() and
memory mapping BPF map contents with writable permissions. The way we
naively do this means we'll hold freeze_mutex for entire duration of all
the mm and VMA manipulations, which is completely unnecessary. This can
potentially also lead to deadlocks, as reported by syzbot in [0].
So, instead, hold freeze_mutex only during writeability checks, bump
(proactively) "write active" count for the map, unlock the mutex and
proceed with mmap logic. And only if something went wrong during mmap
logic, then undo that "write active" counter increment.
[0] https://lore.kernel.org/bpf/678dcbc9.050a0220.303755.0066.GAE@google.com/ |
| In the Linux kernel, the following vulnerability has been resolved:
block: mark GFP_NOIO around sysfs ->store()
sysfs ->store is called with queue freezed, meantime we have several
->store() callbacks(update_nr_requests, wbt, scheduler) to allocate
memory with GFP_KERNEL which may run into direct reclaim code path,
then potential deadlock can be caused.
Fix the issue by marking NOIO around sysfs ->store() |
| A denial of service vulnerability was found in tipc_crypto_key_revoke in net/tipc/crypto.c in the Linux kernel’s TIPC subsystem. This flaw allows guests with local user privileges to trigger a deadlock and potentially crash the system. |
| A denial of service vulnerability due to a deadlock was found in sctp_auto_asconf_init in net/sctp/socket.c in the Linux kernel’s SCTP subsystem. This flaw allows guests with local user privileges to trigger a deadlock and potentially crash the system. |
| This CVE ID has been rejected or withdrawn by its CVE Numbering Authority. |
| In Eclipse ThreadX versions 6.0.1 through 6.5.2.202603, the Module Manager loaders return an overflow error without releasing the Module Manager mutex when a module preamble declares a data or stack size that overflows the allocation arithmetic. Loading such an image blocks every later module load, start, stop and unload from other threads until the system is reset. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: libsas: Fix SMP IO deadlock during HA resume
smp_execute_task_sg() calls pm_runtime_get_sync() on the host before
issuing an SMP command. When that command is itself issued from the HA
resume path, the get_sync() deadlocks: it waits for the ongoing resume
(the device is RPM_RESUMING), while the resume is blocked in
sas_drain_work() waiting for that same SMP IO to complete.
The deadlock needs an expander-attached SATA disk. During
sas_resume_ha() -> sas_drain_work(), DISCE_RESUME -> sas_resume_sata()
-> ata_sas_port_resume() requests ATA_EH_RESET, and the hard reset for
such a disk is done via SMP PHY CONTROL (sas_ata_hard_reset() ->
sas_phy_reset() -> sas_smp_phy_control() ->
smp_execute_task_sg()). Direct-attached SATA resets through
lldd_control_phy() and SSP devices use TMFs, so neither hits this.
Replace the get_sync()/put_sync() pair with
pm_runtime_get_noresume()/pm_runtime_put(). smp_execute_task_sg() only
needs to hold off autosuspend while the SMP is in flight, and it must
not try to resume the host: a sync resume issued from the HA resume path
itself is what deadlocks, and by the time sas_resume_ha() runs, hw_init
has already reinitialized the hardware, so the device is accessible
without one.
The usage reference is still required. Discovery work normally runs
inside an event worker's PM reference, taken at sas_notify_port_event()
notify time and held until the handler has flushed the disco
queue. sas_rediscover_ex_phy() however requeues DISCE_REVALIDATE_DOMAIN
from within the revalidation worker itself, and flush_workqueue() does
not wait for work items queued during execution, so that chained
revalidation runs with no outer PM reference - without the
get_noresume(), its SMP could race autosuspend.
For the BSG path, sas_smp_handler() is the only caller which may find
the host autosuspended: expander SMP requests do not go through any SCSI
device request queue, so nothing else in that path holds the host
awake. Resume it there with pm_runtime_resume_and_get() and check the
result. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: don't hold buffer locks across sync transaction commit in xfs_sync_sb_buf
xfs_sync_sb_buf() holds sb/rtsb buffer locks across a synchronous
xfs_trans_commit(), which flushes the CIL push workqueue internally.
If shutdown occurs during the CIL push, xfs_buf_item_unpin() needs to
lock these buffers to fail them, causing a deadlock:
setlabel: holds buf lock -> flush_workqueue(xfs-cil)
CIL push worker: xfs_buf_item_unpin -> xfs_buf_lock(same buf)
Remove the xfs_trans_bhold() calls so that commit releases the buffer
locks normally. After the sync commit, re-acquire the buffers via
mp->m_sb_bp / mp->m_rtsb_bp for the on-disk writeback. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: connect the session socket without rfcomm_mutex
An RFCOMM connect() issued while a BR/EDR link is being authenticated
makes lockdep report a circular dependency, and the reported cycle is a
real AB/BA between rfcomm_mutex and hdev->lock.
rfcomm_security_cfm() is called from the HCI event path, which already
holds hdev->lock:
hci_rx_work()
hci_event_packet()
hci_cc_read_enc_key_size() [hdev->lock]
hci_encrypt_cfm() [hci_cb_list_lock]
rfcomm_security_cfm() [rfcomm_mutex]
while an RFCOMM connect() from userspace takes the same two locks the
other way round:
rfcomm_sock_connect()
rfcomm_dlc_open() [rfcomm_mutex]
__rfcomm_dlc_open()
rfcomm_session_create()
kernel_connect()
l2cap_sock_connect()
l2cap_chan_connect() [hdev->lock]
WARNING: possible circular locking dependency detected
kworker/u131:1/1128 is trying to acquire lock:
rfcomm_mutex, at: rfcomm_security_cfm+0x31/0x3e0 [rfcomm]
but task is already holding lock:
hci_cb_list_lock, at: hci_cc_read_enc_key_size+0x1d2/0xcc0
Chain exists of:
rfcomm_mutex --> &hdev->lock --> hci_cb_list_lock
hci_auth_complete_evt() and hci_encrypt_change_evt() reach the callback
the same way.
Both orders have to be seen in the same boot, which is why a BR/EDR
connection alone is not enough to show it: a session set up by the
remote side is created by rfcomm_accept_connection() in krfcommd, which
calls kernel_accept() and never takes hdev->lock under rfcomm_mutex.
Connecting a device that authenticates and encrypts the link and then
calling connect() on an RFCOMM socket towards any address - the connect
does not have to succeed, the order is recorded before the page timeout
- reports it every time.
Only the session socket has to be connected with the lock held, and it
does not: nothing else can see the socket before it is put on the
session list. So connect it first and take rfcomm_mutex afterwards,
which removes the rfcomm_mutex -> hdev->lock order for good, rather
than keeping the HCI event path out of rfcomm_mutex.
rfcomm_session_create() becomes rfcomm_session_connect(), which returns
the connected socket without touching the session list, and
rfcomm_dlc_open() adds the session once it holds the lock again. If
another opener added a session for the same pair while this socket was
connecting, that session is used and this socket is dropped.
__rfcomm_dlc_open() now takes the session it should use, and its state
check runs after the lock is re-acquired, so a DLC that was opened or
closed in the meantime is still handled.
Over an existing ACL link the connection can complete before the
session reaches the list, and the wakeup from the socket callback is
then lost, so krfcommd is woken once the session is visible.
Connecting without the lock opens a window in which the socket can be
closed. The DLC is not on a session yet, so rfcomm_dlc_close() finds
nothing to do and returns without touching it, and rfcomm_dlc_open()
would then attach a DLC whose owner is gone. rfcomm_dlc_close() now
marks such a DLC with RFCOMM_CLOSED, and rfcomm_dlc_open() checks the
mark once it holds rfcomm_mutex again and drops the socket instead of
attaching the DLC. The mark is cleared when an open starts, so a DLC
that is reused is not affected. This covers both callers of
rfcomm_dlc_open(), the socket and the tty layer. |
| In the Linux kernel, the following vulnerability has been resolved:
cxgb4/ch_ktls: disable softirqs around tid_list erases
chcr_ktls_cpl_act_open_rpl() inserts into tid_list from the receive path
using xa_insert_bh(). The array is shared by the adapter's connections
and initialized with XA_FLAGS_LOCK_BH. However, chcr_ktls_dev_del() and
the chcr_ktls_dev_add() error path use xa_erase(), which takes the XArray
lock without disabling softirqs.
When cleanup runs with softirqs enabled, a receive softirq for another
connection on the same CPU can interrupt the erase and spin on the lock
held by the interrupted task. Use xa_erase_bh() at both sites to match
the insertion path. |
| 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:
ext4: fix circular lock dependency in ext4_ext_migrate
Move iput(tmp_inode) after ext4_writepages_up_write() to avoid a
circular lock dependency between s_writepages_rwsem and sb_internal
(freeze protection).
The deadlock scenario:
CPU0 (EXT4_IOC_MIGRATE) CPU1 (orphan cleanup during mount)
---- ----
ext4_ext_migrate()
ext4_writepages_down_write()
s_writepages_rwsem (write)
ext4_evict_inode()
sb_start_intwrite() [sb_internal]
...
ext4_writepages()
s_writepages_rwsem (read) [BLOCKED]
iput(tmp_inode)
ext4_evict_inode()
sb_start_intwrite() [BLOCKED]
The tmp_inode is a temporary inode with nlink=0 created solely for
building the extent tree. Its eviction does not require
s_writepages_rwsem protection, so deferring iput() until after
releasing the rwsem is safe. |
| 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:
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:
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:
iommu/amd: move wait_on_sem() out of spinlock
With iommu.strict=1, the existing completion wait path can cause soft
lockups under stressed environment, as wait_on_sem() busy-waits under the
spinlock with interrupts disabled.
Move the completion wait in iommu_completion_wait() out of the spinlock.
wait_on_sem() only polls the hardware-updated cmd_sem and does not require
iommu->lock, so holding the lock during the busy wait unnecessarily
increases contention and extends the time with interrupts disabled. |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet: move async event work off nvmet-wq
For target nvmet_ctrl_free() flushes ctrl->async_event_work.
If nvmet_ctrl_free() runs on nvmet-wq, the flush re-enters workqueue
completion for the same worker:-
A. Async event work queued on nvmet-wq (prior to disconnect):
nvmet_execute_async_event()
queue_work(nvmet_wq, &ctrl->async_event_work)
nvmet_add_async_event()
queue_work(nvmet_wq, &ctrl->async_event_work)
B. Full pre-work chain (RDMA CM path):
nvmet_rdma_cm_handler()
nvmet_rdma_queue_disconnect()
__nvmet_rdma_queue_disconnect()
queue_work(nvmet_wq, &queue->release_work)
process_one_work()
lock((wq_completion)nvmet-wq) <--------- 1st
nvmet_rdma_release_queue_work()
C. Recursive path (same worker):
nvmet_rdma_release_queue_work()
nvmet_rdma_free_queue()
nvmet_sq_destroy()
nvmet_ctrl_put()
nvmet_ctrl_free()
flush_work(&ctrl->async_event_work)
__flush_work()
touch_wq_lockdep_map()
lock((wq_completion)nvmet-wq) <--------- 2nd
Lockdep splat:
============================================
WARNING: possible recursive locking detected
6.19.0-rc3nvme+ #14 Tainted: G N
--------------------------------------------
kworker/u192:42/44933 is trying to acquire lock:
ffff888118a00948 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x26/0x90
but task is already holding lock:
ffff888118a00948 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x53e/0x660
3 locks held by kworker/u192:42/44933:
#0: ffff888118a00948 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x53e/0x660
#1: ffffc9000e6cbe28 ((work_completion)(&queue->release_work)){+.+.}-{0:0}, at: process_one_work+0x1c5/0x660
#2: ffffffff82d4db60 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x62/0x530
Workqueue: nvmet-wq nvmet_rdma_release_queue_work [nvmet_rdma]
Call Trace:
__flush_work+0x268/0x530
nvmet_ctrl_free+0x140/0x310 [nvmet]
nvmet_cq_put+0x74/0x90 [nvmet]
nvmet_rdma_free_queue+0x23/0xe0 [nvmet_rdma]
nvmet_rdma_release_queue_work+0x19/0x50 [nvmet_rdma]
process_one_work+0x206/0x660
worker_thread+0x184/0x320
kthread+0x10c/0x240
ret_from_fork+0x319/0x390
Move async event work to a dedicated nvmet-aen-wq to avoid reentrant
flush on nvmet-wq. |
| In the Linux kernel, the following vulnerability has been resolved:
net/rds: Fix circular locking dependency in rds_tcp_tune
syzbot reported a circular locking dependency in rds_tcp_tune() where
sk_net_refcnt_upgrade() is called while holding the socket lock:
======================================================
WARNING: possible circular locking dependency detected
======================================================
kworker/u10:8/15040 is trying to acquire lock:
ffffffff8e9aaf80 (fs_reclaim){+.+.}-{0:0},
at: __kmalloc_cache_noprof+0x4b/0x6f0
but task is already holding lock:
ffff88805a3c1ce0 (k-sk_lock-AF_INET6){+.+.}-{0:0},
at: rds_tcp_tune+0xd7/0x930
The issue occurs because sk_net_refcnt_upgrade() performs memory
allocation (via get_net_track() -> ref_tracker_alloc()) while the
socket lock is held, creating a circular dependency with fs_reclaim.
Fix this by moving sk_net_refcnt_upgrade() outside the socket lock
critical section. This is safe because the fields modified by the
sk_net_refcnt_upgrade() call (sk_net_refcnt, ns_tracker) are not
accessed by any concurrent code path at this point.
v2:
- Corrected fixes tag
- check patch line wrap nits
- ai commentary nits |
