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.
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.
Published:
2026-08-10
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis and contextual insights are available on OpenCVE Cloud.
Remediation
No vendor fix or workaround currently provided.
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Tracking
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Advisories
No advisories yet.
References
History
Mon, 10 Aug 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-416 |
Mon, 10 Aug 2026 12:30:00 +0000
| Type | Values Removed | Values 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. | |
| Title | ALSA: timer: drain a slave's callback before its master detaches it | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-10T12:00:20.280Z
Reserved: 2026-07-30T09:28:09.374Z
Link: CVE-2026-68201
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OpenCVE Enrichment
Updated: 2026-08-10T17:45:04Z
Weaknesses
-
CWE-416
Use After Free