{"id":"CVE-2026-99103","aliases":[],"title":"workqueue: Fix unbound pool lifetime for pending pwqs","titleSource":"Linux","descriptionSource":"Linux","products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"5a70baec2294e8a7d0fcc4558741c23e752dad5c","status":"affected","lessThan":"6741dd3fd38e47c08bc39d11ef5fa141fa6d0441","versionType":"git"},{"version":"843288afd3cc6f3342659c6cf81fc47684d25563","status":"affected","lessThan":"9f5d5aef3072a33c6f9bfb954bb0cba1c2541849","versionType":"git"},{"version":"5797b1c18919cd9c289ded7954383e499f729ce0","status":"affected","lessThan":"f320b85c90fe5fc9d4d06badd450518323a94a7f","versionType":"git"},{"version":"5797b1c18919cd9c289ded7954383e499f729ce0","status":"affected","lessThan":"3d2ef2b9f4c084ab498494d26495a82f7e15407b","versionType":"git"},{"version":"5797b1c18919cd9c289ded7954383e499f729ce0","status":"affected","lessThan":"cf9c8aaea0d47410df8708bec195889f3a85cd3c","versionType":"git"},{"version":"fc67aebe34f22632ccb22faea48cc4d3134620a2","status":"affected","versionType":"git"},{"version":"6.6.23","status":"affected","lessThan":"6.6.25","versionType":"semver"},{"version":"6.8.2","status":"affected","lessThan":"6.8.4","versionType":"semver"},{"version":"6.7.11","status":"affected","lessThan":"6.8","versionType":"semver"}],"defaultStatus":"unaffected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99103"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.6.25","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.8.4","status":"unaffected","lessThanOrEqual":"6.8.*","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99103"}],"remediation":[],"description":"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   <TASK>\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   </TASK>\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->lock.\n\nRemove the pwq from pending_pwqs before putting the pool.","severity":"unknown","score":null,"published":"2026-10-28T10:34:22.945Z","modified":"2026-10-28T10:34:22.945Z","withdrawn":false,"knownExploited":false,"affected":[],"references":["https://git.kernel.org/stable/c/6741dd3fd38e47c08bc39d11ef5fa141fa6d0441","https://git.kernel.org/stable/c/9f5d5aef3072a33c6f9bfb954bb0cba1c2541849","https://git.kernel.org/stable/c/f320b85c90fe5fc9d4d06badd450518323a94a7f","https://git.kernel.org/stable/c/3d2ef2b9f4c084ab498494d26495a82f7e15407b","https://git.kernel.org/stable/c/cf9c8aaea0d47410df8708bec195889f3a85cd3c"],"sources":[{"name":"CVE","id":"CVE-2026-99103","modified":"2026-10-28T10:34:22.945Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-99103"}],"assessments":[],"sourceAffected":[],"kev":{"status":"not-listed","checkedAt":"2026-10-29T04:05:30.302Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}