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TI-2026-47979 Aliases CVE-2026-68200GHSA-78vp-jqhh-pcc3

ALSA: timer: don't re-enter an instance callback that is still running

Priority LOW 35CWE-362Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: ALSA: timer: don't re-enter an instance callback that is still running The userspace-driven timer (utimer) TRIGGER ioctl calls snd_timer_interrupt() directly with no serialization, so two threads triggering the same utimer can run snd_timer_interrupt() on one snd_timer concurrently. snd_timer_process_callbacks() drops timer->lock around each instance callback and marks the in-flight callback with the single SNDRV_TIMER_IFLG_CALLBACK bit; snd_timer_close_locked() waits on that bit to drain an in-flight callback before freeing the instance. The bit cannot represent two concurrent callbacks: when a second interrupt re-queues an instance whose callback is still running, both run at once, the first to finish clears the bit, and the close-path drain then frees the instance (and its callback_data) while the other callback is still live - a use-after-free reachable by any user able to open /dev/snd/timer, both via a user timer instance and via a sequencer queue timer bound to the utimer. snd_timer_interrupt() sets IFLG_CALLBACK before dropping timer->lock, so a concurrent interrupt already observes it under the lock. Skip re-queuing an instance (and its slaves) to the ack/sack list while its callback is in flight; the accumulated pticks are delivered on the next tick, so no event is lost.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00132 2nd percentileScored 2026-11-07
Fix Fixed Linux (Linux): 6.12.101, 6.18.42, 7.1.6 +1Red Hat: 4 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.12 and later6.12.101, 6.18.42, 7.1.6, 7.2Patch availableCNA
  • Linux VendorLinux Affected 6.12 and later Fixed in 6.12.101, 6.18.42, 7.1.6, 7.2 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.12.101, 6.18.42, 7.1.6, 7.2

Red Hat 4 advisories

  • RHSA-2026:91492 Released 2026-10-28 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) kernel-tools-libs-devel-5.14.0-570.152.1.el9_6, libperf-5.14.0-570.152.1.el9_6
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) kernel-64k-debug-devel-5.14.0-570.152.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.152.1.el9_6, kernel-64k-devel-5.14.0-570.152.1.el9_6 +12
    • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel-5.14.0-570.152.1.el9_6, kernel-64k-5.14.0-570.152.1.el9_6, kernel-64k-core-5.14.0-570.152.1.el9_6 +28
    • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt-5.14.0-570.152.1.el9_6, kernel-rt-64k-5.14.0-570.152.1.el9_6, kernel-rt-64k-core-5.14.0-570.152.1.el9_6 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt-5.14.0-570.152.1.el9_6, kernel-rt-core-5.14.0-570.152.1.el9_6, kernel-rt-debug-5.14.0-570.152.1.el9_6 +11
  • RHSA-2026:88687 Released 2026-10-23 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-64k-debug-devel-6.12.0-55.113.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.113.1.el10_0, kernel-64k-devel-6.12.0-55.113.1.el10_0 +12
    • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel-6.12.0-55.113.1.el10_0, kernel-64k-6.12.0-55.113.1.el10_0, kernel-64k-core-6.12.0-55.113.1.el10_0 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-tools-libs-devel-6.12.0-55.113.1.el10_0, libperf-6.12.0-55.113.1.el10_0
    • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt-6.12.0-55.113.1.el10_0, kernel-rt-64k-6.12.0-55.113.1.el10_0, kernel-rt-64k-core-6.12.0-55.113.1.el10_0 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt-6.12.0-55.113.1.el10_0, kernel-rt-core-6.12.0-55.113.1.el10_0, kernel-rt-debug-6.12.0-55.113.1.el10_0 +11
  • RHSA-2026:68570 Released 2026-09-17 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.49.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.49.1.el9_8, kernel-64k-devel-5.14.0-687.49.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.49.1.el9_8, kernel-64k-5.14.0-687.49.1.el9_8, kernel-64k-core-5.14.0-687.49.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.49.1.el9_8, libperf-5.14.0-687.49.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.49.1.el9_8, kernel-rt-64k-5.14.0-687.49.1.el9_8, kernel-rt-64k-core-5.14.0-687.49.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.49.1.el9_8, kernel-rt-core-5.14.0-687.49.1.el9_8, kernel-rt-debug-5.14.0-687.49.1.el9_8 +9
Show 1 more Red Hat advisories
  • RHSA-2026:68507 Released 2026-09-17 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.56.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.56.1.el10_2, kernel-64k-devel-6.12.0-211.56.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.56.1.el10_2, kernel-64k-6.12.0-211.56.1.el10_2, kernel-64k-core-6.12.0-211.56.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.56.1.el10_2, libperf-6.12.0-211.56.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.56.1.el10_2, kernel-rt-64k-6.12.0-211.56.1.el10_2, kernel-rt-64k-core-6.12.0-211.56.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.56.1.el10_2, kernel-rt-core-6.12.0-211.56.1.el10_2, kernel-rt-debug-6.12.0-211.56.1.el10_2 +9

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:68507
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:68570
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:88687
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:68507
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:68570
Red Hat Enterprise Linux BaseOS EUS (v. 10.0)Fixed RHSA-2026:88687
Red Hat Enterprise Linux BaseOS EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:68507
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:68570
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:88687
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:68507
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:68570
Red Hat Enterprise Linux Real Time EUS (v. 10.0)Fixed RHSA-2026:88687
Red Hat Enterprise Linux Real Time EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:68507
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:68570
Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)Fixed RHSA-2026:88687
Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)Fixed RHSA-2026:91492
Not affected: 5 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9
  • Red Hat Enterprise Linux for NVIDIA 26

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-68200
  2. 2026-10-03 Alias added: GHSA-78vp-jqhh-pcc3
  3. 2026-10-16 CISA SSVC decision points changed
  4. 2026-10-20 Weakness changed · CISA ADP
  5. 2026-10-24 Fix available: RHSA-2026:88687 · Red Hat
  6. 2026-10-24 Fix available: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux BaseOS EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) +2 · Red Hat
  7. 2026-10-29 Affected versions changed · Red Hat
  8. 2026-10-30 Fix available: RHSA-2026:91492 · Red Hat
  9. 2026-10-30 Fix available: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6) +2 · Red Hat

References

Other 4

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences