net: mscc: ocelot: Fix use-after-free caused by cyclic delayed work

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-40003
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-10-18 08:15:34 UTC
Updated2026-10-21 13:18:18 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: net: mscc: ocelot: Fix use-after-free caused by cyclic delayed work The origin code calls cancel_delayed_work() in ocelot_stats_deinit() to cancel the cyclic delayed work item ocelot->stats_work. However, cancel_delayed_work() may fail to cancel the work item if it is already executing. While destroy_workqueue() does wait for all pending work items in the work queue to complete before destroying the work queue, it cannot prevent the delayed work item from being rescheduled within the ocelot_check_stats_work() function. This limitation exists because the delayed work item is only enqueued into the work queue after its timer expires. Before the timer expiration, destroy_workqueue() has no visibility of this pending work item. Once the work queue appears empty, destroy_workqueue() proceeds with destruction. When the timer eventually expires, the delayed work item gets queued again, leading to the following warning: workqueue: cannot queue ocelot_check_stats_work on wq ocelot-switch-stats WARNING: CPU: 2 PID: 0 at kernel/workqueue.c:2255 __queue_work+0x875/0xaf0 ... RIP: 0010:__queue_work+0x875/0xaf0 ... RSP: 0018:ffff88806d108b10 EFLAGS: 00010086 RAX: 0000000000000000 RBX: 0000000000000101 RCX: 0000000000000027 RDX: 0000000000000027 RSI: 0000000000000004 RDI: ffff88806d123e88 RBP: ffffffff813c3170 R08: 0000000000000000 R09: ffffed100da247d2 R10: ffffed100da247d1 R11: ffff88806d123e8b R12: ffff88800c00f000 R13: ffff88800d7285c0 R14: ffff88806d0a5580 R15: ffff88800d7285a0 FS: 0000000000000000(0000) GS:ffff8880e5725000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe18e45ea10 CR3: 0000000005e6c000 CR4: 00000000000006f0 Call Trace: <IRQ> ? kasan_report+0xc6/0xf0 ? __pfx_delayed_work_timer_fn+0x10/0x10 ? __pfx_delayed_work_timer_fn+0x10/0x10 call_timer_fn+0x25/0x1c0 __run_timer_base.part.0+0x3be/0x8c0 ? __pfx_delayed_work_timer_fn+0x10/0x10 ? rcu_sched_clock_irq+0xb06/0x27d0 ? __pfx___run_timer_base.part.0+0x10/0x10 ? try_to_wake_up+0xb15/0x1960 ? _raw_spin_lock_irq+0x80/0xe0 ? __pfx__raw_spin_lock_irq+0x10/0x10 tmigr_handle_remote_up+0x603/0x7e0 ? __pfx_tmigr_handle_remote_up+0x10/0x10 ? sched_balance_trigger+0x1c0/0x9f0 ? sched_tick+0x221/0x5a0 ? _raw_spin_lock_irq+0x80/0xe0 ? __pfx__raw_spin_lock_irq+0x10/0x10 ? tick_nohz_handler+0x339/0x440 ? __pfx_tmigr_handle_remote_up+0x10/0x10 __walk_groups.isra.0+0x42/0x150 tmigr_handle_remote+0x1f4/0x2e0 ? __pfx_tmigr_handle_remote+0x10/0x10 ? ktime_get+0x60/0x140 ? lapic_next_event+0x11/0x20 ? clockevents_program_event+0x1d4/0x2a0 ? hrtimer_interrupt+0x322/0x780 handle_softirqs+0x16a/0x550 irq_exit_rcu+0xaf/0xe0 sysvec_apic_timer_interrupt+0x70/0x80 </IRQ> ... The following diagram reveals the cause of the above warning: CPU 0 (remove) | CPU 1 (delayed work callback) mscc_ocelot_remove() | ocelot_deinit() | ocelot_check_stats_work() ocelot_stats_deinit() | cancel_delayed_work()| ... | queue_delayed_work() destroy_workqueue() | (wait a time) | __queue_work() //UAF The above scenario actually constitutes a UAF vulnerability. The ocelot_stats_deinit() is only invoked when initialization failure or resource destruction, so we must ensure that any delayed work items cannot be rescheduled. Replace cancel_delayed_work() with disable_delayed_work_sync() to guarantee proper cancellation of the delayed work item and ensure completion of any currently executing work before the workqueue is deallocated. A deadlock concern was considered: ocelot_stats_deinit() is called in a process context and is not holding any locks that the delayed work item might also need. Therefore, the use of the _sync() variant is safe here. This bug was identified through static analysis. To reproduce the issue and validate the fix, I simulated ocelot-swit ---truncated---

Risk And Classification

EPSS: 0.002410000 probability, percentile 0.143040000 (date 2026-10-19)

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected a556c76adc052c979ef9e80f0cd3fa1379ff4943 c4672bdc4730d28ee8d9f65386599298047c045e git Not specified
CNA Linux Linux affected a556c76adc052c979ef9e80f0cd3fa1379ff4943 70acdd1eb35ffb3afdcb59e4c3bbb178da411d0f git Not specified
CNA Linux Linux affected a556c76adc052c979ef9e80f0cd3fa1379ff4943 c3363db5d0685a8d077ade706051bbccc75f7e14 git Not specified
CNA Linux Linux affected a556c76adc052c979ef9e80f0cd3fa1379ff4943 bc9ea787079671cb19a8b25ff9f02be5ef6bfcf5 git Not specified
CNA Linux Linux affected 4.18 Not specified
CNA Linux Linux unaffected 4.18 semver Not specified
CNA Linux Linux unaffected 6.6.160 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.54 6.12.* semver Not specified
CNA Linux Linux unaffected 6.17.4 6.17.* semver Not specified
CNA Linux Linux unaffected 6.18 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/70acdd1eb35ffb3afdcb59e4c3bbb178da411d0f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/c3363db5d0685a8d077ade706051bbccc75f7e14 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/bc9ea787079671cb19a8b25ff9f02be5ef6bfcf5 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/c4672bdc4730d28ee8d9f65386599298047c045e 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

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report