diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2019-03-20 16:15:24 -0500 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2019-09-11 14:10:14 +0200 |
| commit | f3acd269c842c035e05fb62951a2fec5a4d6bfce (patch) | |
| tree | 767d1c5857f229b9b9c8428daf659f1d4d89d45e | |
| parent | 8cc4d0f8c508b2a073c8569924d58c691dc6cb5f (diff) | |
ALSA: rawmidi: Fix potential Spectre v1 vulnerability
commit 2b1d9c8f87235f593826b9cf46ec10247741fff9 upstream.
info->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/rawmidi.c:604 __snd_rawmidi_info_select() warn: potential spectre issue 'rmidi->streams' [r] (local cap)
Fix this by sanitizing info->stream before using it to index
rmidi->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://lore.kernel.org/lkml/20180423164740.GY17484@dhcp22.suse.cz/
Change-Id: I2c8b93b82ad4374027a03dc4c73fdf74eee696e6
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | sound/core/rawmidi.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index 930891887..370d44235 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -29,6 +29,7 @@ #include <linux/mutex.h> #include <linux/module.h> #include <linux/delay.h> +#include <linux/nospec.h> #include <sound/rawmidi.h> #include <sound/info.h> #include <sound/control.h> @@ -589,6 +590,7 @@ int snd_rawmidi_info_select(struct snd_card *card, struct snd_rawmidi_info *info return -ENXIO; if (info->stream < 0 || info->stream > 1) return -EINVAL; + info->stream = array_index_nospec(info->stream, 2); pstr = &rmidi->streams[info->stream]; if (pstr->substream_count == 0) return -ENOENT; |