CVE-2026-68201 — ALSA: timer: drain a slave's callback before its master detaches it
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 clo…
Published: 2026-08-10 · CVSS: 7.8 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7