CVE-2026-99103

workqueue: Fix unbound pool lifetime for pending pwqs

cve-program · severity unknownCVSS unknownCheck source for fixed versionsKEV status unknown

Original advisory

cve-program · CVE-2026-99103

Published

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.

Read the publisher's advisory

Affected versions, risk and source history

cve-program · CVE-2026-99103

Published

Linux

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/workqueue.c"
                    ],
                    "versions": [
                        {
                            "version": "5a70baec2294e8a7d0fcc4558741c23e752dad5c",
                            "lessThan": "6741dd3fd38e47c08bc39d11ef5fa141fa6d0441",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "843288afd3cc6f3342659c6cf81fc47684d25563",
                            "lessThan": "9f5d5aef3072a33c6f9bfb954bb0cba1c2541849",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "5797b1c18919cd9c289ded7954383e499f729ce0",
                            "lessThan": "390b9542fe670b8936738140ef9f349df6adeab6",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "5797b1c18919cd9c289ded7954383e499f729ce0",
                            "lessThan": "f320b85c90fe5fc9d4d06badd450518323a94a7f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "5797b1c18919cd9c289ded7954383e499f729ce0",
                            "lessThan": "3d2ef2b9f4c084ab498494d26495a82f7e15407b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "5797b1c18919cd9c289ded7954383e499f729ce0",
                            "lessThan": "cf9c8aaea0d47410df8708bec195889f3a85cd3c",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "fc67aebe34f22632ccb22faea48cc4d3134620a2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6.6.23",
                            "lessThan": "6.6.25",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.8.2",
                            "lessThan": "6.8.4",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.7.11",
                            "lessThan": "6.8",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ]
                }

Linux

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/workqueue.c"
                    ],
                    "versions": [
                        {
                            "version": "6.9",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.9",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.25",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.8.4",
                            "lessThanOrEqual": "6.8.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.115",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.59",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.13",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON