• Takashi Iwai's avatar
    ALSA: seq: oss: Don't drain at closing a client · 197b958c
    Takashi Iwai authored
    The OSS sequencer client tries to drain the pending events at
    releasing.  Unfortunately, as spotted by syzkaller fuzzer, this may
    lead to an unkillable process state when the event has been queued at
    the far future.  Since the process being released can't be signaled
    any longer, it remains and waits for the echo-back event in that far
    future.
    
    Back to history, the draining feature was implemented at the time we
    misinterpreted POSIX definition for blocking file operation.
    Actually, such a behavior is superfluous at release, and we should
    just release the device as is instead of keeping it up forever.
    
    This patch just removes the draining call that may block the release
    for too long time unexpectedly.
    
    BugLink: http://lkml.kernel.org/r/CACT4Y+Y4kD-aBGj37rf-xBw9bH3GMU6P+MYg4W1e-s-paVD2pg@mail.gmail.comReported-by: default avatarDmitry Vyukov <dvyukov@google.com>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    197b958c
seq_oss.c 7.17 KB