diff options
| author | Takashi Iwai <tiwai@suse.de> | 2022-05-06 12:10:09 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-12 12:23:48 +0200 |
| commit | fbeb492694ce0441053de57699e1e2b7bc148a69 (patch) | |
| tree | 8918d2004b7fddad2fde6078fc74db809219ac06 /include | |
| parent | f098f8b9820fe3f2e41aefc4329dfe8a3859d1c1 (diff) | |
ALSA: pcm: Fix races among concurrent hw_params and hw_free calls
commit 92ee3c60ec9fe64404dc035e7c41277d74aa26cb upstream.
Currently we have neither proper check nor protection against the
concurrent calls of PCM hw_params and hw_free ioctls, which may result
in a UAF. Since the existing PCM stream lock can't be used for
protecting the whole ioctl operations, we need a new mutex to protect
those racy calls.
This patch introduced a new mutex, runtime->buffer_mutex, and applies
it to both hw_params and hw_free ioctl code paths. Along with it, the
both functions are slightly modified (the mmap_count check is moved
into the state-check block) for code simplicity.
Reported-by: Hu Jiahui <kirin.say@gmail.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220322170720.3529-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[OP: backport to 5.4: adjusted context]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/sound/pcm.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index bbe6eb1ff5d2..24273d0f770b 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -395,6 +395,7 @@ struct snd_pcm_runtime { wait_queue_head_t sleep; /* poll sleep */ wait_queue_head_t tsleep; /* transfer sleep */ struct fasync_struct *fasync; + struct mutex buffer_mutex; /* protect for buffer changes */ /* -- private section -- */ void *private_data; |