{"id":"CVE-2026-90276","published":"2026-09-17T17:17:24.247","lastModified":"2026-09-17T17:17:24.247","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmd/md-llbitmap: stop daemon timer rearm on destroy\n\nllbitmap_destroy() deletes pending_timer before flushing\nmd_llbitmap_io_wq. However, daemon_work can still be queued or running\nafter the timer has been deleted, and the daemon path can arm\npending_timer again when it finds dirty chunks that are not ready to\nflush yet.\n\nIf that happens during teardown, pending_timer can remain armed after\nllbitmap is freed and later dereference freed memory.\n\nAdd a BITMAP_SHUTDOWN bit to llbitmap->flags, set it before deleting\nthe timer, and make the timer and daemon paths stop queueing or rearming\nwork once teardown starts. Cancel daemon_work before flushing the shared\nworkqueue so no already queued daemon instance can race with the free.\nUse timer_shutdown_sync() so a daemon instance that passed the shutdown\ncheck before teardown cannot rearm the timer afterward.\n\nBITMAP_SHUTDOWN is a runtime-only state. Mask it out when reading and\nupdating the llbitmap superblock so the shutdown state is never loaded\nfrom disk or persisted to disk.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/5553d64e01d9a995be6c3de38501c6dd4ceede3b","tags":[]},{"url":"https://git.kernel.org/stable/c/bb7f92d58fca9a9f06f3f51a82481c5f0bbbd46c","tags":[]},{"url":"https://git.kernel.org/stable/c/c55aa6c17f019b6296952d336939891efa084c06","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}