{"id":"CVE-2026-90276","summary":"md/md-llbitmap: stop daemon timer rearm on destroy","details":"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-\u003eflags, 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.","modified":"2026-09-19T03:47:28.822519775Z","published":"2026-09-17T16:08:08.697Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90276.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5553d64e01d9a995be6c3de38501c6dd4ceede3b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bb7f92d58fca9a9f06f3f51a82481c5f0bbbd46c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c55aa6c17f019b6296952d336939891efa084c06"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90276.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90276"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5ab829f1971dc99f2aac10846c378e67fc875abc"},{"fixed":"c55aa6c17f019b6296952d336939891efa084c06"},{"fixed":"bb7f92d58fca9a9f06f3f51a82481c5f0bbbd46c"},{"fixed":"5553d64e01d9a995be6c3de38501c6dd4ceede3b"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90276.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90276.json"}}],"schema_version":"1.9.0"}