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authorAlexey Khoroshilov <khoroshilov@ispras.ru>2015-04-18 02:53:25 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-17 09:51:33 -0700
commitcccea7f5c40ef96866d02be01e0712985940d102 (patch)
treeb4ab3543f79d3b86b05cf44230be9954e0906184 /kernel
parent6186ada9e4801a27068373fae01d089e41054823 (diff)
downloadedison-v3.10-cccea7f5c40ef96866d02be01e0712985940d102.tar.gz
sound/oss: fix deadlock in sequencer_ioctl(SNDCTL_SEQ_OUTOFBAND)
commit bc26d4d06e337ade069f33d3f4377593b24e6e36 upstream. A deadlock can be initiated by userspace via ioctl(SNDCTL_SEQ_OUTOFBAND) on /dev/sequencer with TMR_ECHO midi event. In this case the control flow is: sound_ioctl() -> case SND_DEV_SEQ: case SND_DEV_SEQ2: sequencer_ioctl() -> case SNDCTL_SEQ_OUTOFBAND: spin_lock_irqsave(&lock,flags); play_event(); -> case EV_TIMING: seq_timing_event() -> case TMR_ECHO: seq_copy_to_input() -> spin_lock_irqsave(&lock,flags); It seems that spin_lock_irqsave() around play_event() is not necessary, because the only other call location in seq_startplay() makes the call without acquiring spinlock. So, the patch just removes spinlocks around play_event(). By the way, it removes unreachable code in seq_timing_event(), since (seq_mode == SEQ_2) case is handled in the beginning. Compile tested only. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Takashi Iwai <tiwai@suse.de> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
0 files changed, 0 insertions, 0 deletions