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| author | Takashi Iwai | 2018-03-05 22:06:09 +0100 |
|---|---|---|
| committer | Takashi Iwai | 2018-03-08 12:05:37 +0100 |
| commit | 7bd80091567789f1c0cb70eb4737aac8bcd2b6b9 (patch) | |
| tree | f89b49a8c3e7efa67e1983274ffcd60889fdf574 /sound/core/seq/seq_memory.h | |
| parent | ALSA: seq: Don't allow resizing pool in use (diff) | |
| download | kernel-qcow2-linux-7bd80091567789f1c0cb70eb4737aac8bcd2b6b9.tar.gz kernel-qcow2-linux-7bd80091567789f1c0cb70eb4737aac8bcd2b6b9.tar.xz kernel-qcow2-linux-7bd80091567789f1c0cb70eb4737aac8bcd2b6b9.zip | |
ALSA: seq: More protection for concurrent write and ioctl races
This patch is an attempt for further hardening against races between
the concurrent write and ioctls. The previous fix d15d662e89fc
("ALSA: seq: Fix racy pool initializations") covered the race of the
pool initialization at writer and the pool resize ioctl by the
client->ioctl_mutex (CVE-2018-1000004). However, basically this mutex
should be applied more widely to the whole write operation for
avoiding the unexpected pool operations by another thread.
The only change outside snd_seq_write() is the additional mutex
argument to helper functions, so that we can unlock / relock the given
mutex temporarily during schedule() call for blocking write.
Fixes: d15d662e89fc ("ALSA: seq: Fix racy pool initializations")
Reported-by: 范龙飞 <long7573@126.com>
Reported-by: Nicolai Stange <nstange@suse.de>
Reviewed-and-tested-by: Nicolai Stange <nstange@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/seq/seq_memory.h')
| -rw-r--r-- | sound/core/seq/seq_memory.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sound/core/seq/seq_memory.h b/sound/core/seq/seq_memory.h index 32f959c17786..3abe306c394a 100644 --- a/sound/core/seq/seq_memory.h +++ b/sound/core/seq/seq_memory.h @@ -66,7 +66,8 @@ struct snd_seq_pool { void snd_seq_cell_free(struct snd_seq_event_cell *cell); int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event, - struct snd_seq_event_cell **cellp, int nonblock, struct file *file); + struct snd_seq_event_cell **cellp, int nonblock, + struct file *file, struct mutex *mutexp); /* return number of unused (free) cells */ static inline int snd_seq_unused_cells(struct snd_seq_pool *pool) |