CVE-2026-90276

In the Linux kernel, the following vulnerability has been resolved: md/md-llbitmap: stop daemon timer rearm on destroy llbitmap_destroy() deletes pending_timer before flushing md_llbitmap_io_wq. However, daemon_work can still be queued or running after the timer has been deleted, and the daemon path can arm pending_timer again when it finds dirty chunks that are not ready to flush yet. If that happens during teardown, pending_timer can remain armed after llbitmap is freed and later dereference freed memory. Add a BITMAP_SHUTDOWN bit to llbitmap->flags, set it before deleting the timer, and make the timer and daemon paths stop queueing or rearming work once teardown starts. Cancel daemon_work before flushing the shared workqueue so no already queued daemon instance can race with the free. Use timer_shutdown_sync() so a daemon instance that passed the shutdown check before teardown cannot rearm the timer afterward. BITMAP_SHUTDOWN is a runtime-only state. Mask it out when reading and updating the llbitmap superblock so the shutdown state is never loaded from disk or persisted to disk.

CVSS

No CVSS.

References

Link	Resource
https://git.kernel.org/stable/c/5553d64e01d9a995be6c3de38501c6dd4ceede3b
https://git.kernel.org/stable/c/bb7f92d58fca9a9f06f3f51a82481c5f0bbbd46c
https://git.kernel.org/stable/c/c55aa6c17f019b6296952d336939891efa084c06

Configurations

No configuration.

History

17 Sep 2026, 17:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-17 17:17

Updated : 2026-09-17 17:17

NVD link : CVE-2026-90276

Mitre link : CVE-2026-90276

CVE.ORG link : CVE-2026-90276

JSON object : View

Products Affected

No product.

CWE

No CWE.

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