--- id: CVE-2026-68202 title: |- In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: close a re-opened queue timer in the destructor queue_delete() closes the queue timer, then frees it summary: |- In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: close a re-opened queue timer in the destructor queue_delete() closes the queue timer, then frees it. snd_seq_timer_close() clears 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 - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68202.json - url: 'https://access.redhat.com/security/cve/CVE-2026-68202' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2513245' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-68202' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-68202' - url: >- https://lore.kernel.org/linux-cve-announce/2026081011-CVE-2026-68202-e7fa@gregkh/T - url: 'https://access.redhat.com/errata/RHSA-2026:88477' - url: 'https://access.redhat.com/errata/RHSA-2026:87805' - url: 'https://access.redhat.com/errata/RHSA-2026:87375' - url: 'https://access.redhat.com/errata/RHSA-2026:87374' tags: - nvd - csaf - vex - red-hat - cve.org epss: 0.00177 epssPercentile: 0.07184 ingestedAt: '2026-08-23T13:48:06.652Z' vendor: Red Hat product: Red Hat Enterprise Linux 9 affected: - enterprise_linux 10 - enterprise_linux 7 - enterprise_linux 8 - enterprise_linux 9 - openshift_container_platform 4 - enterprise_linux 6 cwe: - CWE-825 scores: nvd: 7.8 vendor: 7 cna: 7.8 ssvc: exploitation: none automatable: 'no' technicalImpact: total timestamp: '2026-10-16T15:45:51.106270Z' patched: - 10base_smtv - enterprise_linux_appstream_v_10 - enterprise_linux_appstream_v_9 - enterprise_linux_baseos_v_10 - enterprise_linux_baseos_v_8 - enterprise_linux_baseos_v_9 - enterprise_linux_codeready_linux_builder_v_10 - enterprise_linux_crb_v_8 - enterprise_linux_codeready_linux_builder_v_9 - enterprise_linux_hidden_v_10 - enterprise_linux_real_time_for_nfv_v_10 - enterprise_linux_nfv_v_8 - enterprise_linux_real_time_for_nfv_v_9 - enterprise_linux_real_time_v_10 - enterprise_linux_rt_v_8 - enterprise_linux_real_time_v_9 --- ## Overview In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: close a re-opened queue timer in the destructor queue_delete() closes the queue timer, then frees it. snd_seq_timer_close() clears q->timer->timeri. snd_use_lock_sync() then drains borrowers, and snd_seq_timer_delete() frees q->timer. A borrower can re-open the timer inside that window. A SET_QUEUE_CLIENT that took a queueptr() use_lock reference before the queue was unlinked runs snd_seq_timer_open() after the close. Open refuses re-open only while timeri is set, and the close just cleared it, so it re-opens timeri. snd_seq_timer_delete() does not close that instance. Its snd_seq_timer_stop() is a no-op, because running was cleared first. So it frees q->timer with the instance still live. The queue is freed next. The instance stays on the global timer with callback_data pointing at the freed queue. A non-owner START on the unlocked queue arms it. The next tick derefs the freed queue in snd_seq_timer_interrupt(). Reachable by an unprivileged user with access to /dev/snd/seq. No CAP and no queue ownership required. Close any lingering instance in the destructor. There, ->timeri can no longer change: the queue is unlinked and all use_lock borrowers have drained, so no snd_seq_queue_use() can re-open it. Close it before clearing q->timer. snd_timer_close() waits for any in-flight snd_seq_timer_interrupt() to finish, and that callback still reads q->timer (via snd_seq_check_queue()), so q->timer must stay valid until it drains. ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Vendor advisories - **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4, Red Hat Enterprise Linux 6 · no fix planned: Red Hat OpenShift Container Platform 4, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68202.json) - **RHSA-2026:88477** · Red Hat · fixed in: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Hidden (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), … · released 2026-10-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:88477) - **RHSA-2026:87805** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-10-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:87805) - **RHSA-2026:87375** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87375) - **RHSA-2026:87374** · Red Hat · fixed in: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8) · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87374)