Description
In the Linux kernel, the following vulnerability has been resolved:

block: stop the timeout timer when releasing a never added disk

disk_release() undoes blk_mq_init_allocated_queue() for a disk whose
probe failed before add_disk(), but it only calls blk_mq_exit_queue().
Nothing there stops q->timeout, and that timer rolls forward: it stays
pending until it next expires, not until the last request completes.
So if the driver issued any I/O before adding the disk, the
request_queue is freed while still linked into a timer wheel bucket.

Commit 6f8191fdf41d ("block: simplify disk shutdown") dropped the
blk_cleanup_queue() call that used to stop it. __del_gendisk() and
blk_mq_destroy_queue() still do; only the probe failure path lost it.

nvme gets there because nvme_update_ns_info() submits Report Zones or
FDP io-mgmt-recv on ns->queue before the disk is added, so a later
failure - a concurrent reset setting NVME_CTRL_FROZEN, or
device_add_disk() failing - lands in put_disk() with the timer armed:

BUG: KASAN: slab-use-after-free in detach_if_pending+0x30c/0x340
Write of size 8 at addr ffff888004d71310 by task kworker/u8:2/37
__timer_delete_sync+0x156/0x240 kernel/time/timer.c:1621
blk_sync_queue+0x22/0x40 block/blk-core.c:222
nvme_sync_queues+0x100/0x150 drivers/nvme/host/core.c:5362
nvme_reset_work+0x138/0x930 drivers/nvme/host/pci.c:3264

Allocated by task 34:
__blk_mq_alloc_disk+0x33/0x100 block/blk-mq.c:4462
nvme_alloc_ns+0x290/0x3870 drivers/nvme/host/core.c:4146

Freed by task 0:
blk_free_queue_rcu+0x3a/0x50 block/blk-core.c:254
rcu_core+0xc10/0x1730 kernel/rcu/tree.c:2857

The queue being synced there is ctrl->admin_q, only a victim sharing a
timer wheel bucket with the freed queue's dangling entry; other runs
tripped in enqueue_timer(), __run_timers() or blk_mq_timeout_work().
Failing nvme_alloc_ns() with a debug patch makes it deterministic: one
leaked timer trips KASAN within seconds, while 1987 patched releases
produced no splat.

Stop the timer and the queue work items before blk_mq_exit_queue(), like
blk_mq_destroy_queue() does.

Found by FuzzNvme.
Published: 2026-08-26
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Wed, 26 Aug 2026 17:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Wed, 26 Aug 2026 14:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: block: stop the timeout timer when releasing a never added disk disk_release() undoes blk_mq_init_allocated_queue() for a disk whose probe failed before add_disk(), but it only calls blk_mq_exit_queue(). Nothing there stops q->timeout, and that timer rolls forward: it stays pending until it next expires, not until the last request completes. So if the driver issued any I/O before adding the disk, the request_queue is freed while still linked into a timer wheel bucket. Commit 6f8191fdf41d ("block: simplify disk shutdown") dropped the blk_cleanup_queue() call that used to stop it. __del_gendisk() and blk_mq_destroy_queue() still do; only the probe failure path lost it. nvme gets there because nvme_update_ns_info() submits Report Zones or FDP io-mgmt-recv on ns->queue before the disk is added, so a later failure - a concurrent reset setting NVME_CTRL_FROZEN, or device_add_disk() failing - lands in put_disk() with the timer armed: BUG: KASAN: slab-use-after-free in detach_if_pending+0x30c/0x340 Write of size 8 at addr ffff888004d71310 by task kworker/u8:2/37 __timer_delete_sync+0x156/0x240 kernel/time/timer.c:1621 blk_sync_queue+0x22/0x40 block/blk-core.c:222 nvme_sync_queues+0x100/0x150 drivers/nvme/host/core.c:5362 nvme_reset_work+0x138/0x930 drivers/nvme/host/pci.c:3264 Allocated by task 34: __blk_mq_alloc_disk+0x33/0x100 block/blk-mq.c:4462 nvme_alloc_ns+0x290/0x3870 drivers/nvme/host/core.c:4146 Freed by task 0: blk_free_queue_rcu+0x3a/0x50 block/blk-core.c:254 rcu_core+0xc10/0x1730 kernel/rcu/tree.c:2857 The queue being synced there is ctrl->admin_q, only a victim sharing a timer wheel bucket with the freed queue's dangling entry; other runs tripped in enqueue_timer(), __run_timers() or blk_mq_timeout_work(). Failing nvme_alloc_ns() with a debug patch makes it deterministic: one leaked timer trips KASAN within seconds, while 1987 patched releases produced no splat. Stop the timer and the queue work items before blk_mq_exit_queue(), like blk_mq_destroy_queue() does. Found by FuzzNvme.
Title block: stop the timeout timer when releasing a never added disk
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-26T14:37:43.293Z

Reserved: 2026-08-26T14:34:25.770Z

Link: CVE-2026-80589

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-26T15:17:15.283

Modified: 2026-08-26T15:17:15.283

Link: CVE-2026-80589

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-26T17:00:04Z

Weaknesses