# CVE-2026-99103: linux: In the Linux kernel, the following vulnerability has been resolved:  workqueue: Fix unbound pool lifetime for pending...

CVE-2026-99103 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-99103, released November 3, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-99103
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 28, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-99103](https://patchblox.com/security/data/fix/linux/debian-cve-2026-99103.md) | Nov 3, 2026 |
| Linux | linux Debian 14 | 7.2.13-1 | [DEBIAN-CVE-2026-99103](https://patchblox.com/security/data/fix/linux/debian-cve-2026-99103.md) | Nov 3, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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