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Fencer Vulns
high 7.8

CVE-2026-68202 json

ALSA: seq: close a re-opened queue timer in the destructor

published 2026-08-10 2 mo ago modified 2026-10-19 20 d ago also EUVD-2026-55303

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

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_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.

Patch / fix

  • Linux Linux 5.10.266, 5.15.217, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2
  • linux Debian 12 6.1.187-1
  • linux Debian 13 6.12.101-1
  • linux Debian 14 7.1.6-1
  • linux-6.12 Debian 12 6.12.101-1~deb12u1

debian advisories DEBIAN-CVE-2026-68202

  • linux Ubuntu 22.04 LTS 5.15.0-202.212
  • linux Ubuntu 24.04 LTS 6.8.0-147.147
  • linux Ubuntu 26.04 LTS 7.0.0-38.38
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1119.126
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1120.130
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79

ubuntu advisories UBUNTU-CVE-2026-68202

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.189.1
  • kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.189.1
  • kernel-source SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.189.1
  • kernel-default SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +3 more 5.14.21-150500.55.189.1
  • kernel-obs-build SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.189.1
  • kernel-default-base SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.189.1.150500.6.87.4
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1

suse advisories SUSE-SU-2026:4595-1SUSE-SU-2026:4586-1SUSE-SU-2026:4254-1SUSE-SU-2026:4570-1SUSE-SU-2026:4561-1SUSE-SU-2026:4559-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.38.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.38.1

opensuse advisories openSUSE-SU-2026:21910-1

  • kernel AlmaLinux 9 5.14.0-687.60.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.60.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.60.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.60.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.60.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.60.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.60.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.60.1.el9_8

almalinux advisories ALSA-2026:87805ALSA-2026:88477ALSA-2026:87374ALSA-2026:87375

  • kernel Rocky Linux 10 6.12.0-211.68.1.el10_2
  • kernel Rocky Linux 9 5.14.0-687.60.1.el9_8
  • kernel-rt Rocky Linux 8 4.18.0-553.177.1.rt7.518.el8_10
  • kernel Rocky Linux 8 4.18.0-553.177.1.el8_10

rocky linux advisories RLSA-2026:88477RLSA-2026:87805RLSA-2026:87374RLSA-2026:87375

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-68202 updated cvss 7.0

kernel: ALSA: seq: close a re-opened queue timer in the destructor

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    under investigation
  • Red Hat Enterprise Linux kernel-modules-internal 6.12.0-211.68.1.el10_2
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.60.1.el9_8, perf 5.14.0-687.60.1.el9_8, rtla 5.14.0-687.60.1.el9_8, python3-perf 5.14.0-687.60.1.el9_8, kernel-devel-matched 5.14.0-687.60.1.el9_8, kernel-64k-devel-matched 5.14.0-687.60.1.el9_8, +7 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87805
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.68.1.el10_2, perf 6.12.0-211.68.1.el10_2, rtla 6.12.0-211.68.1.el10_2, python3-perf 6.12.0-211.68.1.el10_2, kernel-devel-matched 6.12.0-211.68.1.el10_2, kernel-64k-devel-matched 6.12.0-211.68.1.el10_2, +7 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.177.1.el8_10, kernel 4.18.0-553.177.1.el8_10, bpftool 4.18.0-553.177.1.el8_10, kernel-core 4.18.0-553.177.1.el8_10, kernel-tools 4.18.0-553.177.1.el8_10, python3-perf 4.18.0-553.177.1.el8_10, +15 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87375
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.60.1.el9_8, kernel-64k 5.14.0-687.60.1.el9_8, kernel-core 5.14.0-687.60.1.el9_8, kernel-tools 5.14.0-687.60.1.el9_8, kernel-modules 5.14.0-687.60.1.el9_8, kernel-64k-core 5.14.0-687.60.1.el9_8, +27 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87805
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.68.1.el10_2, kernel-64k 6.12.0-211.68.1.el10_2, kernel-core 6.12.0-211.68.1.el10_2, kernel-tools 6.12.0-211.68.1.el10_2, kernel-modules 6.12.0-211.68.1.el10_2, kernel-64k-core 6.12.0-211.68.1.el10_2, +28 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
show 11 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.60.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.60.1.el9_8
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87805
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.68.1.el10_2
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.177.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.177.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.177.1.el8_10
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87375
  • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal 6.12.0-211.68.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.68.1.el10_2
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-kvm 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-core 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-modules 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-kvm 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-core 4.18.0-553.177.1.rt7.518.el8_10, +4 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87374
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.60.1.el9_8, kernel-rt-64k 5.14.0-687.60.1.el9_8, kernel-rt-core 5.14.0-687.60.1.el9_8, kernel-rt-modules 5.14.0-687.60.1.el9_8, kernel-rt-64k-core 5.14.0-687.60.1.el9_8, kernel-rt-debug-core 5.14.0-687.60.1.el9_8, +14 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87805
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.68.1.el10_2, kernel-rt-64k 6.12.0-211.68.1.el10_2, kernel-rt-core 6.12.0-211.68.1.el10_2, kernel-rt-modules 6.12.0-211.68.1.el10_2, kernel-rt-64k-core 6.12.0-211.68.1.el10_2, kernel-rt-debug-core 6.12.0-211.68.1.el10_2, +14 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.60.1.el9_8, kernel-rt-core 5.14.0-687.60.1.el9_8, kernel-rt-modules 5.14.0-687.60.1.el9_8, kernel-rt-debug-core 5.14.0-687.60.1.el9_8, kernel-rt-modules-core 5.14.0-687.60.1.el9_8, kernel-rt-debug-modules 5.14.0-687.60.1.el9_8, +4 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87805
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.68.1.el10_2, kernel-rt-core 6.12.0-211.68.1.el10_2, kernel-rt-modules 6.12.0-211.68.1.el10_2, kernel-rt-debug-core 6.12.0-211.68.1.el10_2, kernel-rt-modules-core 6.12.0-211.68.1.el10_2, kernel-rt-debug-modules 6.12.0-211.68.1.el10_2, +4 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:88477
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-core 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-modules 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-core 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-modules 4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-modules-extra 4.18.0-553.177.1.rt7.518.el8_10, +2 more
    fixed: vendor fix “To mitigate this issue, prevent module snd_seq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2026:87374
  • Red Hat Enterprise Linux for NVIDIA 26 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
23 d ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.