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| author | Takashi Iwai <tiwai@suse.de> | 2017-02-06 15:09:48 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-03-16 02:18:47 +0000 |
| commit | c723076373dac50287fba6ccd1067301b67dbfa4 (patch) | |
| tree | 6c8b6df1a6c64aa9652c6722f87c42d2fe94a584 /sound | |
| parent | 61b48f3b16447b4e966a71f52e1ce28eabec9343 (diff) | |
| download | linux-stable-c723076373dac50287fba6ccd1067301b67dbfa4.tar.gz linux-stable-c723076373dac50287fba6ccd1067301b67dbfa4.tar.bz2 linux-stable-c723076373dac50287fba6ccd1067301b67dbfa4.zip | |
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>
[bwh: Backported to 3.2: deleted log statement is slightly different]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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 e0e683cd3926..9f20d3c24d76 100644 --- a/sound/core/seq/seq_memory.c +++ b/sound/core/seq/seq_memory.c @@ -421,7 +421,6 @@ 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; @@ -434,14 +433,8 @@ 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); |