CVE-2026-68201
ALSA: timer: drain a slave's callback before its master detaches it
Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: timer: drain a slave's callback before its master detaches it snd_timer_close_locked() drains the closing instance's own in-flight callback (IFLG_CALLBACK) before freeing it, but not its slaves'. When a master instance is closed, remove_slave_links() clears each slave's ->timer; the slave's own close then reads timer == NULL and takes the branch that skips the drain entirely (snd_timer_stop_slave() also no-ops on a NULL timer). So a slave whose callback is still running when the master is closed is freed underneath the live callback, leading to use-after-free. Drain the slaves too before remove_slave_links() severs them. snd_timer_stop() has already taken this instance off the active list, so no new slave callback can be queued. Take the slaves off the ack list so a pending one can't fire either, then wait for any that is already in flight.
INFO
Published Date :
Aug. 10, 2026, 1:20 p.m.
Last Modified :
Aug. 17, 2026, 5:18 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Apply the Linux kernel patch for ALSA: timer: drain a slave's callback.
- Ensure slave callbacks are drained before master detachment.
- Remove slaves from the ack list before draining.
- Wait for any in-flight slave callbacks to complete.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-68201.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-68201 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-68201
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-68201 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-68201 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': 'cd461bcfcdf8d6b6b5365941c1d3859f8bc77aa0', 'versionType': 'git'}, {'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': '426c0ff1c433d6030610ad4f9375746dfe931caa', 'versionType': 'git'}, {'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': '2b298997786876b225cff2446e11a0fa6f602f6d', 'versionType': 'git'}, {'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': 'bdefe1346a8e6b8dc8593406dc2617e985fcbcab', 'versionType': 'git'}], 'programFiles': ['sound/core/timer.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.12'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.12', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.101', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.42', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.6', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc5', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['sound/core/timer.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': 'cd461bcfcdf8d6b6b5365941c1d3859f8bc77aa0', 'versionType': 'git'}, {'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': '426c0ff1c433d6030610ad4f9375746dfe931caa', 'versionType': 'git'}, {'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': '2b298997786876b225cff2446e11a0fa6f602f6d', 'versionType': 'git'}, {'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': 'bdefe1346a8e6b8dc8593406dc2617e985fcbcab', 'versionType': 'git'}], 'programFiles': ['sound/core/timer.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.12'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.12', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.101', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.42', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.6', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['sound/core/timer.c'], 'defaultStatus': 'affected'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 10, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': 'cd461bcfcdf8d6b6b5365941c1d3859f8bc77aa0', 'versionType': 'git'}, {'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': '426c0ff1c433d6030610ad4f9375746dfe931caa', 'versionType': 'git'}, {'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': '2b298997786876b225cff2446e11a0fa6f602f6d', 'versionType': 'git'}, {'status': 'affected', 'version': '37745918e0e7575bc40f38da93a99b9fa6406224', 'lessThan': 'bdefe1346a8e6b8dc8593406dc2617e985fcbcab', 'versionType': 'git'}], 'programFiles': ['sound/core/timer.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.12'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.12', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.101', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.42', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.6', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc5', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['sound/core/timer.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: ALSA: timer: drain a slave's callback before its master detaches it snd_timer_close_locked() drains the closing instance's own in-flight callback (IFLG_CALLBACK) before freeing it, but not its slaves'. When a master instance is closed, remove_slave_links() clears each slave's ->timer; the slave's own close then reads timer == NULL and takes the branch that skips the drain entirely (snd_timer_stop_slave() also no-ops on a NULL timer). So a slave whose callback is still running when the master is closed is freed underneath the live callback, leading to use-after-free. Drain the slaves too before remove_slave_links() severs them. snd_timer_stop() has already taken this instance off the active list, so no new slave callback can be queued. Take the slaves off the ack list so a pending one can't fire either, then wait for any that is already in flight. Added Reference https://git.kernel.org/stable/c/2b298997786876b225cff2446e11a0fa6f602f6d Added Reference https://git.kernel.org/stable/c/426c0ff1c433d6030610ad4f9375746dfe931caa Added Reference https://git.kernel.org/stable/c/bdefe1346a8e6b8dc8593406dc2617e985fcbcab Added Reference https://git.kernel.org/stable/c/cd461bcfcdf8d6b6b5365941c1d3859f8bc77aa0