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author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-12-18 11:52:16 -0600 |
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committer | Ben Hutchings <ben@decadent.org.uk> | 2019-04-04 16:13:58 +0100 |
commit | c05d2eacd080e7b550a3af1ef30433259a978a6c (patch) | |
tree | ea8ad7deea9072061920f9c193bdd64082a1123a /sound | |
parent | 7650fd8d8b6a1bebbcdb6bd47d4df313df11d066 (diff) | |
download | linux-stable-c05d2eacd080e7b550a3af1ef30433259a978a6c.tar.gz linux-stable-c05d2eacd080e7b550a3af1ef30433259a978a6c.tar.bz2 linux-stable-c05d2eacd080e7b550a3af1ef30433259a978a6c.zip |
ALSA: emu10k1: Fix potential Spectre v1 vulnerabilities
commit 5ae4f61f012a097df93de2285070ec8e34716d29 upstream.
ipcm->substream 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/pci/emu10k1/emufx.c:1031 snd_emu10k1_ipcm_poke() warn: potential spectre issue 'emu->fx8010.pcm' [r] (local cap)
sound/pci/emu10k1/emufx.c:1075 snd_emu10k1_ipcm_peek() warn: potential spectre issue 'emu->fx8010.pcm' [r] (local cap)
Fix this by sanitizing ipcm->substream before using it to index emu->fx8010.pcm
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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'sound')
-rw-r--r-- | sound/pci/emu10k1/emufx.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/sound/pci/emu10k1/emufx.c b/sound/pci/emu10k1/emufx.c index acce8c76eff0..7ce0b7bc6409 100644 --- a/sound/pci/emu10k1/emufx.c +++ b/sound/pci/emu10k1/emufx.c @@ -36,6 +36,7 @@ #include <linux/init.h> #include <linux/mutex.h> #include <linux/moduleparam.h> +#include <linux/nospec.h> #include <sound/core.h> #include <sound/tlv.h> @@ -1001,6 +1002,8 @@ static int snd_emu10k1_ipcm_poke(struct snd_emu10k1 *emu, if (ipcm->substream >= EMU10K1_FX8010_PCM_COUNT) return -EINVAL; + ipcm->substream = array_index_nospec(ipcm->substream, + EMU10K1_FX8010_PCM_COUNT); if (ipcm->channels > 32) return -EINVAL; pcm = &emu->fx8010.pcm[ipcm->substream]; @@ -1047,6 +1050,8 @@ static int snd_emu10k1_ipcm_peek(struct snd_emu10k1 *emu, if (ipcm->substream >= EMU10K1_FX8010_PCM_COUNT) return -EINVAL; + ipcm->substream = array_index_nospec(ipcm->substream, + EMU10K1_FX8010_PCM_COUNT); pcm = &emu->fx8010.pcm[ipcm->substream]; mutex_lock(&emu->fx8010.lock); spin_lock_irq(&emu->reg_lock); |