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authorTakashi Iwai <tiwai@suse.de>2017-02-06 15:09:48 +0100
committerTakashi Iwai <tiwai@suse.de>2017-02-06 15:09:48 +0100
commit37a7ea4a9b81f6a864c10a7cb0b96458df5310a3 (patch)
tree11144552593b9656fa4cad7bde945e5bb1a5ad4a /sound
parentd5adbfcd5f7bcc6fa58a41c5c5ada0e5c826ce2c (diff)
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ALSA: seq: Don't handle loop timeout at snd_seq_pool_done()
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> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
-rw-r--r--sound/core/seq/seq_memory.c9
1 files changed, 1 insertions, 8 deletions
diff --git a/sound/core/seq/seq_memory.c b/sound/core/seq/seq_memory.c
index c850345c43b5..dfa5156f3585 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) {
- pr_warn("ALSA: 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);