diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2019-03-20 18:42:01 -0500 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2019-09-11 14:26:36 +0200 |
| commit | af8543463d699874fb15b0297de26aa9ad4f8f1b (patch) | |
| tree | ab5df7e7dce5cbb75d0db001005abcaad58c916b | |
| parent | 26925894221e73d1b4f0d93d1b0cadfbce41a917 (diff) | |
ALSA: seq: oss: Fix Spectre v1 vulnerability
commit c709f14f0616482b67f9fbcb965e1493a03ff30b upstream.
dev 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/seq/oss/seq_oss_synth.c:626 snd_seq_oss_synth_make_info() warn: potential spectre issue 'dp->synths' [w] (local cap)
Fix this by sanitizing dev before using it to index dp->synths.
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: Iee6ea225b165fec2d01a09c5d24eea22099a3a53
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>
| -rw-r--r-- | sound/core/seq/oss/seq_oss_synth.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/sound/core/seq/oss/seq_oss_synth.c b/sound/core/seq/oss/seq_oss_synth.c index 4a09c3085..9d2ea0947 100644 --- a/sound/core/seq/oss/seq_oss_synth.c +++ b/sound/core/seq/oss/seq_oss_synth.c @@ -607,13 +607,14 @@ int snd_seq_oss_synth_make_info(struct seq_oss_devinfo *dp, int dev, struct synth_info *inf) { struct seq_oss_synth *rec; + struct seq_oss_synthinfo *info = get_synthinfo_nospec(dp, dev); - if (dev < 0 || dev >= dp->max_synthdev) + if (!info) return -ENXIO; - if (dp->synths[dev].is_midi) { + if (info->is_midi) { struct midi_info minf; - snd_seq_oss_midi_make_info(dp, dp->synths[dev].midi_mapped, &minf); + snd_seq_oss_midi_make_info(dp, info->midi_mapped, &minf); inf->synth_type = SYNTH_TYPE_MIDI; inf->synth_subtype = 0; inf->nr_voices = 16; |