In the Linux kernel, the following vulnerability has been resolved:
workqueue: Fix unbound pool lifetime for pending pwqs
KASAN reports a use-after-free of an unbound worker_pool in
node_activate_pending_pwq():
BUG: KASAN: slab-use-after-free in _raw_spin_trylock+0x6d/0x120
Read of size 4 at addr ffff8880089ce000 by task kworker/u22:0/318
CPU: 1 UID: 0 PID: 318 Comm: kworker/u22:0 Not tainted 7.2.0 #1 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: 0x0 (flush-8:0)
Call Trace:
<TASK>
dump_stack_lvl+0x53/0x70
print_report+0xce/0x610
kasan_report+0xce/0x100
_raw_spin_trylock+0x6d/0x120
pwq_dec_nr_in_flight+0x4b4/0xcb0
process_one_work+0x921/0x11a0
worker_thread+0x4d0/0xd20
kthread+0x2de/0x3c0
ret_from_fork+0x3aa/0x620
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 311:
alloc_pwq+0x439/0xca0
apply_wqattrs_prepare+0x75e/0xd10
apply_workqueue_attrs_locked+0x44/0xa0
wq_nice_store+0x350/0x450
Freed by task 0:
kfree+0x127/0x3b0
rcu_core+0x523/0x1780
handle_softirqs+0x1b3/0x610
Last potentially related work creation:
put_unbound_pool+0x3f3/0x7d0
pwq_release_workfn+0x494/0x8e0
kthread_worker_fn+0x1ff/0x790
Canceling the last inactive work skips pwq_dec_nr_active(), so an empty
pwq can remain on pending_pwqs when its refcnt reaches zero.
pwq_release_workfn() currently puts the pool before removing that pwq.
If this drops the last pool reference, the pool can be RCU-freed while
the pwq remains reachable, and node_activate_pending_pwq() may trylock
the freed pool->lock.
Remove the pwq from pending_pwqs before putting the pool.
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
|
No data.
No data.
References
History
Wed, 28 Oct 2026 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-416 |
Wed, 28 Oct 2026 12:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux linux
|
|
| Vendors & Products |
Linux linux
|
Wed, 28 Oct 2026 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: workqueue: Fix unbound pool lifetime for pending pwqs KASAN reports a use-after-free of an unbound worker_pool in node_activate_pending_pwq(): BUG: KASAN: slab-use-after-free in _raw_spin_trylock+0x6d/0x120 Read of size 4 at addr ffff8880089ce000 by task kworker/u22:0/318 CPU: 1 UID: 0 PID: 318 Comm: kworker/u22:0 Not tainted 7.2.0 #1 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: 0x0 (flush-8:0) Call Trace: <TASK> dump_stack_lvl+0x53/0x70 print_report+0xce/0x610 kasan_report+0xce/0x100 _raw_spin_trylock+0x6d/0x120 pwq_dec_nr_in_flight+0x4b4/0xcb0 process_one_work+0x921/0x11a0 worker_thread+0x4d0/0xd20 kthread+0x2de/0x3c0 ret_from_fork+0x3aa/0x620 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 311: alloc_pwq+0x439/0xca0 apply_wqattrs_prepare+0x75e/0xd10 apply_workqueue_attrs_locked+0x44/0xa0 wq_nice_store+0x350/0x450 Freed by task 0: kfree+0x127/0x3b0 rcu_core+0x523/0x1780 handle_softirqs+0x1b3/0x610 Last potentially related work creation: put_unbound_pool+0x3f3/0x7d0 pwq_release_workfn+0x494/0x8e0 kthread_worker_fn+0x1ff/0x790 Canceling the last inactive work skips pwq_dec_nr_active(), so an empty pwq can remain on pending_pwqs when its refcnt reaches zero. pwq_release_workfn() currently puts the pool before removing that pwq. If this drops the last pool reference, the pool can be RCU-freed while the pwq remains reachable, and node_activate_pending_pwq() may trylock the freed pool->lock. Remove the pwq from pending_pwqs before putting the pool. | |
| Title | workqueue: Fix unbound pool lifetime for pending pwqs | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2026-10-28T10:34:22.945Z
Updated: 2026-10-28T10:34:22.945Z
Reserved: 2026-09-25T10:25:14.391Z
Link: CVE-2026-99103
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-28T11:17:29.593
Modified: 2026-10-28T11:17:29.593
Link: CVE-2026-99103
Redhat
No data.