ALSA: timer: Forcibly close timer instances at closing
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: ALSA: timer: Forcibly close timer instances at closing When snd_timer object is freed via snd_timer_free() and still pending snd_timer_instance objects are assigned to the timer object, it tries to unlink all instances and just set NULL to each ti->timer, then releases the resources immediately. The problem is, however, when there are slave timer instances that are associated with a master instance linked to this timer: namely, those slave instances still point to the freed timer object although the master instance is unlinked, which may lead to user-after-free. The bug can be easily triggered particularly when a new userspace-driven timers (CONFIG_SND_UTIMER) is involved, since it can create and delete the timer object via a simple file open/close, while the other applications may keep accessing to that timer. This patch is an attempt to paper over the problem above: now instead of just unlinking, call snd_timer_close[_locked]() forcibly for each pending timer instance, so that all assigned slave timer instances are properly detached, too. Since snd_timer_close() might be called later by the driver that created that instance, the check of SNDRV_TIMER_IFLG_DEAD is added at the beginning, too.
Why it matters now
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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.12 and later | 6.12.94, 6.18.36, 7.0.13, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 6.12 and later Fixed in 6.12.94, 6.18.36, 7.0.13, 7.1 Patch available CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.12 to before 6.12.94; 6.13 to before 6.18.36; 6.19 to before 7.0.13 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | 7.1 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | 7.1 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | 7.1 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* | 7.1 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* | 7.1 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* | 7.1 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc7:*:*:*:*:*:* | 7.1 rc7 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.12 to before 6.12.94; 6.13 to before 6.18.36; 6.19 to before 7.0.13 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* Versions 7.1 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* Versions 7.1 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* Versions 7.1 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* Versions 7.1 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* Versions 7.1 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* Versions 7.1 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc7:*:*:*:*:*:* Versions 7.1 rc7 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.12.94, 6.18.36, 7.0.13, 7.1
Red Hat 2 advisories
- RHSA-2026:68570 Released 2026-09-17 · Red Hat rating Importantkernel 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
- RHSA-2026:68507 Released 2026-09-17 · Red Hat rating Importantkernel 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: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| 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 BaseOS (v. 10) | Fixed | RHSA-2026:68507 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:68570 |
| 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 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 for NFV (v. 10) | Fixed | RHSA-2026:68507 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:68570 |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-53193
- 2026-10-03 Alias added: GHSA-r56g-vpx5-3639
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-19 Weakness changed · CISA ADP
- 2026-10-29 Affected versions changed · Red Hat
References
More Linux Kernel vulnerabilities
- 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-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
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-53193 · CVE Program
- CVE-2026-53193 · NVD
- FIRST EPSS
- GHSA-r56g-vpx5-3639 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-53193 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences