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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2019-03-21 00:15:24 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2019-03-21 15:21:15 +0300 |
| commit | 2b1d9c8f87235f593826b9cf46ec10247741fff9 (patch) | |
| tree | c592769a24939ce800b7038fa4faba8908679506 /sound/core | |
| parent | 667a8f73753908c4d0171e52b71774f9be5d6713 (diff) | |
| download | linux-2b1d9c8f87235f593826b9cf46ec10247741fff9.tar.xz | |
ALSA: rawmidi: Fix potential Spectre v1 vulnerability
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/
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -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 ee601d7f0926..c0690d1ecd55 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -30,6 +30,7 @@ #include <linux/module.h> #include <linux/delay.h> #include <linux/mm.h> +#include <linux/nospec.h> #include <sound/rawmidi.h> #include <sound/info.h> #include <sound/control.h> @@ -601,6 +602,7 @@ static int __snd_rawmidi_info_select(struct snd_card *card, 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; |