On Wed, 03 Nov 2021 04:35:17 +0100, Wang Wensheng wrote: > > When the timer instance was add into ack_list but was not currently in > process, the user could stop it via snd_timer_stop1() without delete it > from the ack_list. Then the user could free the timer instance and when > it was actually processed UAF occurred. > > This issue could be reproduced via testcase snd_timer01 in ltp - running > several instances of that testcase at the same time. > > What I actually met was that the ack_list of the timer broken and the > kernel went into deadloop with irqoff. That could be detected by > hardlockup detector on board or when we run it on qemu, we could use gdb > to dump the ack_list when the console has no response. > > To fix this issue, we delete the timer instance from ack_list and > active_list unconditionally in snd_timer_stop1(). > > Signed-off-by: Wang Wensheng <wangwensheng4@xxxxxxxxxx> > Suggested-by: Takashi Iwai <tiwai@xxxxxxx> Thanks, applied now. Takashi
