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| author | Takashi Iwai <tiwai@suse.de> | 2017-02-06 17:09:48 +0300 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2017-02-16 13:44:46 +0300 |
| commit | 7f262f3f9b4c1e65b6c079dd2441ea4297e1b7d0 (patch) | |
| tree | b2a5ae0a20d3a4f8add6fdc4d72214d7d59371f0 /sound | |
| parent | a5d412df0ec103883ae59c285adced190db0794a (diff) | |
| download | linux-7f262f3f9b4c1e65b6c079dd2441ea4297e1b7d0.tar.xz | |
ALSA: seq: Don't handle loop timeout at snd_seq_pool_done()
commit 37a7ea4a9b81f6a864c10a7cb0b96458df5310a3 upstream.
snd_seq_pool_done() syncs with closing of all opened threads, but it
aborts the wait loop with a timeout, and proceeds to the release
resource even if not all threads have been closed. The timeout was 5
seconds, and if you run a crazy stuff, it can exceed easily, and may
result in the access of the invalid memory address -- this is what
syzkaller detected in a bug report.
As a fix, let the code graduate from naiveness, simply remove the loop
timeout.
BugLink: http://lkml.kernel.org/r/CACT4Y+YdhDV2H5LLzDTJDVF-qiYHUHhtRaW4rbb4gUhTCQB81w@mail.gmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/core/seq/seq_memory.c | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/sound/core/seq/seq_memory.c b/sound/core/seq/seq_memory.c index 652350e2533f..7204c0f1700b 100644 --- a/sound/core/seq/seq_memory.c +++ b/sound/core/seq/seq_memory.c @@ -419,7 +419,6 @@ int snd_seq_pool_done(struct snd_seq_pool *pool) { unsigned long flags; struct snd_seq_event_cell *ptr; - int max_count = 5 * HZ; if (snd_BUG_ON(!pool)) return -EINVAL; @@ -432,14 +431,8 @@ int snd_seq_pool_done(struct snd_seq_pool *pool) if (waitqueue_active(&pool->output_sleep)) wake_up(&pool->output_sleep); - while (atomic_read(&pool->counter) > 0) { - if (max_count == 0) { - snd_printk(KERN_WARNING "snd_seq_pool_done timeout: %d cells remain\n", atomic_read(&pool->counter)); - break; - } + while (atomic_read(&pool->counter) > 0) schedule_timeout_uninterruptible(1); - max_count--; - } /* release all resources */ spin_lock_irqsave(&pool->lock, flags); |