workqueue: Fix unbound pool lifetime for pending pwqs
Summary
| CVE | CVE-2026-99103 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-28 11:17:29 UTC |
| Updated | 2026-10-30 13:21:45 UTC |
| 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. |
Risk And Classification
EPSS: 0.001730000 probability, percentile 0.067350000 (date 2026-10-31)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 5a70baec2294e8a7d0fcc4558741c23e752dad5c 6741dd3fd38e47c08bc39d11ef5fa141fa6d0441 git | Not specified |
| CNA | Linux | Linux | affected 843288afd3cc6f3342659c6cf81fc47684d25563 9f5d5aef3072a33c6f9bfb954bb0cba1c2541849 git | Not specified |
| CNA | Linux | Linux | affected 5797b1c18919cd9c289ded7954383e499f729ce0 390b9542fe670b8936738140ef9f349df6adeab6 git | Not specified |
| CNA | Linux | Linux | affected 5797b1c18919cd9c289ded7954383e499f729ce0 f320b85c90fe5fc9d4d06badd450518323a94a7f git | Not specified |
| CNA | Linux | Linux | affected 5797b1c18919cd9c289ded7954383e499f729ce0 3d2ef2b9f4c084ab498494d26495a82f7e15407b git | Not specified |
| CNA | Linux | Linux | affected 5797b1c18919cd9c289ded7954383e499f729ce0 cf9c8aaea0d47410df8708bec195889f3a85cd3c git | Not specified |
| CNA | Linux | Linux | affected fc67aebe34f22632ccb22faea48cc4d3134620a2 git | Not specified |
| CNA | Linux | Linux | affected 6.6.23 6.6.25 semver | Not specified |
| CNA | Linux | Linux | affected 6.8.2 6.8.4 semver | Not specified |
| CNA | Linux | Linux | affected 6.7.11 6.8 semver | Not specified |
| CNA | Linux | Linux | affected 6.9 | Not specified |
| CNA | Linux | Linux | unaffected 6.9 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.25 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.8.4 6.8.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.115 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.59 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.13 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/cf9c8aaea0d47410df8708bec195889f3a85cd3c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/390b9542fe670b8936738140ef9f349df6adeab6 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/9f5d5aef3072a33c6f9bfb954bb0cba1c2541849 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/3d2ef2b9f4c084ab498494d26495a82f7e15407b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/f320b85c90fe5fc9d4d06badd450518323a94a7f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/6741dd3fd38e47c08bc39d11ef5fa141fa6d0441 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.