CVE-2026-99103 (GCVE-0-2026-99103)

Vulnerability from cvelistv5 – Published: 2026-10-28 10:34 – Updated: 2026-10-28 10:34
VLAI
Title
workqueue: Fix unbound pool lifetime for pending pwqs
Summary
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.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 7033 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 5a70baec2294e8a7d0fcc4558741c23e752dad5c , < 6741dd3fd38e47c08bc39d11ef5fa141fa6d0441 (git)
Affected: 843288afd3cc6f3342659c6cf81fc47684d25563 , < 9f5d5aef3072a33c6f9bfb954bb0cba1c2541849 (git)
Affected: 5797b1c18919cd9c289ded7954383e499f729ce0 , < f320b85c90fe5fc9d4d06badd450518323a94a7f (git)
Affected: 5797b1c18919cd9c289ded7954383e499f729ce0 , < 3d2ef2b9f4c084ab498494d26495a82f7e15407b (git)
Affected: 5797b1c18919cd9c289ded7954383e499f729ce0 , < cf9c8aaea0d47410df8708bec195889f3a85cd3c (git)
Affected: fc67aebe34f22632ccb22faea48cc4d3134620a2 (git)
Affected: 6.6.23 , < 6.6.25 (semver)
Affected: 6.8.2 , < 6.8.4 (semver)
Affected: 6.7.11 , < 6.8 (semver)
guessed Create a notification for this product.
Linux Linux Affected: 6.9
Unaffected: 0 , < 6.9 (semver)
Unaffected: 6.6.25 , ≤ 6.6.* (semver)
Unaffected: 6.8.4 , ≤ 6.8.* (semver)
Unaffected: 6.18.59 , ≤ 6.18.* (semver)
Unaffected: 7.2.13 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nworkqueue: Fix unbound pool lifetime for pending pwqs\n\nKASAN reports a use-after-free of an unbound worker_pool in\nnode_activate_pending_pwq():\n\n  BUG: KASAN: slab-use-after-free in _raw_spin_trylock+0x6d/0x120\n  Read of size 4 at addr ffff8880089ce000 by task kworker/u22:0/318\n\n  CPU: 1 UID: 0 PID: 318 Comm: kworker/u22:0 Not tainted 7.2.0 #1 PREEMPT(lazy)\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\n  Workqueue:  0x0 (flush-8:0)\n  Call Trace:\n   \u003cTASK\u003e\n   dump_stack_lvl+0x53/0x70\n   print_report+0xce/0x610\n   kasan_report+0xce/0x100\n   _raw_spin_trylock+0x6d/0x120\n   pwq_dec_nr_in_flight+0x4b4/0xcb0\n   process_one_work+0x921/0x11a0\n   worker_thread+0x4d0/0xd20\n   kthread+0x2de/0x3c0\n   ret_from_fork+0x3aa/0x620\n   ret_from_fork_asm+0x1a/0x30\n   \u003c/TASK\u003e\n\n  Allocated by task 311:\n   alloc_pwq+0x439/0xca0\n   apply_wqattrs_prepare+0x75e/0xd10\n   apply_workqueue_attrs_locked+0x44/0xa0\n   wq_nice_store+0x350/0x450\n\n  Freed by task 0:\n   kfree+0x127/0x3b0\n   rcu_core+0x523/0x1780\n   handle_softirqs+0x1b3/0x610\n\n  Last potentially related work creation:\n   put_unbound_pool+0x3f3/0x7d0\n   pwq_release_workfn+0x494/0x8e0\n   kthread_worker_fn+0x1ff/0x790\n\nCanceling the last inactive work skips pwq_dec_nr_active(), so an empty\npwq can remain on pending_pwqs when its refcnt reaches zero.\npwq_release_workfn() currently puts the pool before removing that pwq.\nIf this drops the last pool reference, the pool can be RCU-freed while\nthe pwq remains reachable, and node_activate_pending_pwq() may trylock\nthe freed pool-\u003elock.\n\nRemove the pwq from pending_pwqs before putting the pool."
        }
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      "providerMetadata": {
        "dateUpdated": "2026-10-28T10:34:22.945Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/cf9c8aaea0d47410df8708bec195889f3a85cd3c"
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      "title": "workqueue: Fix unbound pool lifetime for pending pwqs",
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    "datePublished": "2026-10-28T10:34:22.945Z",
    "dateReserved": "2026-09-25T10:25:14.391Z",
    "dateUpdated": "2026-10-28T10:34:22.945Z",
    "state": "PUBLISHED"
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        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nworkqueue: Fix unbound pool lifetime for pending pwqs\n\nKASAN reports a use-after-free of an unbound worker_pool in\nnode_activate_pending_pwq():\n\n  BUG: KASAN: slab-use-after-free in _raw_spin_trylock+0x6d/0x120\n  Read of size 4 at addr ffff8880089ce000 by task kworker/u22:0/318\n\n  CPU: 1 UID: 0 PID: 318 Comm: kworker/u22:0 Not tainted 7.2.0 #1 PREEMPT(lazy)\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\n  Workqueue:  0x0 (flush-8:0)\n  Call Trace:\n   \u003cTASK\u003e\n   dump_stack_lvl+0x53/0x70\n   print_report+0xce/0x610\n   kasan_report+0xce/0x100\n   _raw_spin_trylock+0x6d/0x120\n   pwq_dec_nr_in_flight+0x4b4/0xcb0\n   process_one_work+0x921/0x11a0\n   worker_thread+0x4d0/0xd20\n   kthread+0x2de/0x3c0\n   ret_from_fork+0x3aa/0x620\n   ret_from_fork_asm+0x1a/0x30\n   \u003c/TASK\u003e\n\n  Allocated by task 311:\n   alloc_pwq+0x439/0xca0\n   apply_wqattrs_prepare+0x75e/0xd10\n   apply_workqueue_attrs_locked+0x44/0xa0\n   wq_nice_store+0x350/0x450\n\n  Freed by task 0:\n   kfree+0x127/0x3b0\n   rcu_core+0x523/0x1780\n   handle_softirqs+0x1b3/0x610\n\n  Last potentially related work creation:\n   put_unbound_pool+0x3f3/0x7d0\n   pwq_release_workfn+0x494/0x8e0\n   kthread_worker_fn+0x1ff/0x790\n\nCanceling the last inactive work skips pwq_dec_nr_active(), so an empty\npwq can remain on pending_pwqs when its refcnt reaches zero.\npwq_release_workfn() currently puts the pool before removing that pwq.\nIf this drops the last pool reference, the pool can be RCU-freed while\nthe pwq remains reachable, and node_activate_pending_pwq() may trylock\nthe freed pool-\u003elock.\n\nRemove the pwq from pending_pwqs before putting the pool."
          }
        ],
        "id": "CVE-2026-99103",
        "lastModified": "2026-10-28T11:17:29.593",
        "metrics": {},
        "published": "2026-10-28T11:17:29.593",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/3d2ef2b9f4c084ab498494d26495a82f7e15407b"
          },
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          },
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            "url": "https://git.kernel.org/stable/c/f320b85c90fe5fc9d4d06badd450518323a94a7f"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-10-29T07:53:15+00:00",
      "cve": "CVE-2026-99103",
      "id": "CVE-2026-99103",
      "initial_release_date": "2026-10-28T00:00:00+00:00",
      "product_status:known_affected": "199",
      "product_status:known_not_affected": "79",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: workqueue: Fix unbound pool lifetime for pending pwqs",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-99103.json",
      "version": "3"
    }
  }
}



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