ALSA: virmidi: Fix too long output trigger loop

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commit 50e9ffb199 upstream.

The virmidi output trigger tries to parse the all available bytes and
process sequencer events as much as possible.  In a normal situation,
this is supposed to be relatively short, but a program may give a huge
buffer and it'll take a long time in a single spin lock, which may
eventually lead to a soft lockup.

This patch simply adds a workaround, a cond_resched() call in the loop
if applicable.  A better solution would be to move the event processor
into a work, but let's put a duct-tape quickly at first.

Reported-and-tested-by: Dae R. Jeong <threeearcat@gmail.com>
Reported-by: syzbot+619d9f40141d826b097e@syzkaller.appspotmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

...

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Takashi Iwai 2018-07-26 14:27:59 +02:00 • committed by Ben Hutchings

parent 56b0417092

commit dc06b2632c

1 changed files with 10 additions and 0 deletions

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sound/core/seq/seq_virmidi.c

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