{"id":"CVE-2026-68202","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: close a re-opened queue timer in the destructor\n\nqueue_delete() closes the queue timer, then frees it","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: close a re-opened queue timer in the destructor\n\nqueue_delete() closes the queue timer, then frees it. snd_seq_timer_close()\nclears q->timer->timeri. snd_use…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","published":"2026-08-10","updated":"2026-08-23","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-68202","references":[{"url":"https://git.kernel.org/stable/c/24f0cabf173539f048946c8fc221131dc221f277","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2c4dc0ed50b05cd847a4b34b8cebf0775f19aeb9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/31a6163e301d832060f8236f1ed17cbc1ca198df","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6a10025c7fd09a7d2af37a3ae1da188569fce470","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7478ef94b49bc9789cf1a003deec58b42283dde4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9d9be6fc30f384f92c4e1b8ed40bd9d4796b7833","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b7feeaca1f53b10df9b4de9eaf611767ca70dc92","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fb40d03ed792a8a8bf77aa0ee15df57b0ff78b07","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00176,"epssPercentile":0.07375,"ingestedAt":"2026-08-23T13:48:06.652Z","slug":"CVE-2026-68202","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: close a re-opened queue timer in the destructor\n\nqueue_delete() closes the queue timer, then frees it. snd_seq_timer_close()\nclears q->timer->timeri. snd_use_lock_sync() then drains borrowers, and\nsnd_seq_timer_delete() frees q->timer.\n\nA borrower can re-open the timer inside that window. A SET_QUEUE_CLIENT\nthat took a queueptr() use_lock reference before the queue was unlinked\nruns snd_seq_timer_open() after the close. Open refuses re-open only while\ntimeri is set, and the close just cleared it, so it re-opens timeri.\n\nsnd_seq_timer_delete() does not close that instance. Its snd_seq_timer_stop()\nis a no-op, because running was cleared first. So it frees q->timer with the\ninstance still live. The queue is freed next.\n\nThe instance stays on the global timer with callback_data pointing at the\nfreed queue. A non-owner START on the unlocked queue arms it. The next tick\nderefs the freed queue in snd_seq_timer_interrupt().\n\nReachable by an unprivileged user with access to /dev/snd/seq. No CAP and\nno queue ownership required.\n\nClose any lingering instance in the destructor. There, ->timeri can no\nlonger change: the queue is unlinked and all use_lock borrowers have\ndrained, so no snd_seq_queue_use() can re-open it. Close it before clearing\nq->timer. snd_timer_close() waits for any in-flight snd_seq_timer_interrupt()\nto finish, and that callback still reads q->timer (via snd_seq_check_queue()),\nso q->timer must stay valid until it drains.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}