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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
37745918e0e7575bc40f38da93a99b9fa6406224 to < cd461bcfcdf8d6b6b5365941c1d3859f8bc77aa0affected37745918e0e7575bc40f38da93a99b9fa6406224 to < 426c0ff1c433d6030610ad4f9375746dfe931caaaffected37745918e0e7575bc40f38da93a99b9fa6406224 to < 2b298997786876b225cff2446e11a0fa6f602f6daffected37745918e0e7575bc40f38da93a99b9fa6406224 to < bdefe1346a8e6b8dc8593406dc2617e985fcbcabaffected
Linux Linux
Default version status: affected
6.12affected0 to < 6.12unaffected6.12.101 to ≤ 6.12.*unaffected6.18.42 to ≤ 6.18.*unaffected7.1.6 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected