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| author | Takashi Iwai <tiwai@suse.de> | 2017-03-21 13:56:04 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2017-03-21 14:01:10 +0100 |
| commit | c520ff3d03f0b5db7146d9beed6373ad5d2a5e0e (patch) | |
| tree | ded14dbde99a6392416d92153ebfa248a2493616 /sound/core/seq/seq_fifo.c | |
| parent | c6736a94d0e527ddc0d1eb99dbc59886a9ecf471 (diff) | |
| download | linux-c520ff3d03f0b5db7146d9beed6373ad5d2a5e0e.tar.gz linux-c520ff3d03f0b5db7146d9beed6373ad5d2a5e0e.tar.bz2 linux-c520ff3d03f0b5db7146d9beed6373ad5d2a5e0e.zip | |
ALSA: seq: Fix racy cell insertions during snd_seq_pool_done()
When snd_seq_pool_done() is called, it marks the closing flag to
refuse the further cell insertions. But snd_seq_pool_done() itself
doesn't clear the cells but just waits until all cells are cleared by
the caller side. That is, it's racy, and this leads to the endless
stall as syzkaller spotted.
This patch addresses the racy by splitting the setup of pool->closing
flag out of snd_seq_pool_done(), and calling it properly before
snd_seq_pool_done().
BugLink: http://lkml.kernel.org/r/CACT4Y+aqqy8bZA1fFieifNxR2fAfFQQABcBHj801+u5ePV0URw@mail.gmail.com
Reported-and-tested-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/seq/seq_fifo.c')
| -rw-r--r-- | sound/core/seq/seq_fifo.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/sound/core/seq/seq_fifo.c b/sound/core/seq/seq_fifo.c index 448efd4e980e..33980d1c8037 100644 --- a/sound/core/seq/seq_fifo.c +++ b/sound/core/seq/seq_fifo.c @@ -72,6 +72,9 @@ void snd_seq_fifo_delete(struct snd_seq_fifo **fifo) return; *fifo = NULL; + if (f->pool) + snd_seq_pool_mark_closing(f->pool); + snd_seq_fifo_clear(f); /* wake up clients if any */ |