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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-12-12 15:36:28 -0600 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2018-12-13 09:14:33 +0100 |
| commit | 94ffb030b6d31ec840bb811be455dd2e26a4f43e (patch) | |
| tree | de66c4b427f2f361df27e5cd5f0a84fd2ae41070 /sound/core/pcm.c | |
| parent | 4aea96f4237cea0c51a8bc87c0db31f0f932f1f0 (diff) | |
| download | linux-94ffb030b6d31ec840bb811be455dd2e26a4f43e.tar.bz2 | |
ALSA: pcm: Fix potential Spectre v1 vulnerability
stream is indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.
This issue was detected with the help of Smatch:
sound/core/pcm.c:140 snd_pcm_control_ioctl() warn: potential spectre issue 'pcm->streams' [r] (local cap)
Fix this by sanitizing stream before using it to index pcm->streams
Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].
[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: stable@vger.kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/pcm.c')
| -rw-r--r-- | sound/core/pcm.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sound/core/pcm.c b/sound/core/pcm.c index fdb9b92fc8d6..01b9d62eef14 100644 --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -25,6 +25,7 @@ #include <linux/time.h> #include <linux/mutex.h> #include <linux/device.h> +#include <linux/nospec.h> #include <sound/core.h> #include <sound/minors.h> #include <sound/pcm.h> @@ -129,6 +130,7 @@ static int snd_pcm_control_ioctl(struct snd_card *card, return -EFAULT; if (stream < 0 || stream > 1) return -EINVAL; + stream = array_index_nospec(stream, 2); if (get_user(subdevice, &info->subdevice)) return -EFAULT; mutex_lock(®ister_mutex); |