{"id":"CVE-2026-90276","title":"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","summary":"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…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 5ab829f1971dc99f2aac10846c378e67fc875abc < c55aa6c17f019b6296952d336939891efa084c06","Linux >= 5ab829f1971dc99f2aac10846c378e67fc875abc < bb7f92d58fca9a9f06f3f51a82481c5f0bbbd46c","Linux >= 5ab829f1971dc99f2aac10846c378e67fc875abc < 5553d64e01d9a995be6c3de38501c6dd4ceede3b","Linux 6.18"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:17:24.247","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90276","references":[{"url":"https://git.kernel.org/stable/c/5553d64e01d9a995be6c3de38501c6dd4ceede3b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bb7f92d58fca9a9f06f3f51a82481c5f0bbbd46c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c55aa6c17f019b6296952d336939891efa084c06","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-17T16:21:47.836Z","epss":0.00198,"epssPercentile":0.09866,"slug":"CVE-2026-90276","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}