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authorTakashi Iwai <tiwai@suse.de>2018-04-24 07:56:07 +0200
committerTakashi Iwai <tiwai@suse.de>2018-04-25 10:37:47 +0200
commit7f054a5bee0987f1e2d4e59daea462421c76f2cb (patch)
tree31ef4ea6ea8237bba834fcbedac06c8463318338
parent69fa6f19b95597618ab30438a27b67ad93daa7c7 (diff)
downloadlinux-7f054a5bee0987f1e2d4e59daea462421c76f2cb.tar.bz2
ALSA: opl3: Hardening for potential Spectre v1
As recently Smatch suggested, one place in OPL3 driver may expand the array directly from the user-space value with speculation: sound/drivers/opl3/opl3_synth.c:476 snd_opl3_set_voice() warn: potential spectre issue 'snd_opl3_regmap' This patch puts array_index_nospec() for hardening against it. BugLink: https://marc.info/?l=linux-kernel&m=152411496503418&w=2 Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--sound/drivers/opl3/opl3_synth.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/sound/drivers/opl3/opl3_synth.c b/sound/drivers/opl3/opl3_synth.c
index ddcc1a325a61..42920a243328 100644
--- a/sound/drivers/opl3/opl3_synth.c
+++ b/sound/drivers/opl3/opl3_synth.c
@@ -21,6 +21,7 @@
#include <linux/slab.h>
#include <linux/export.h>
+#include <linux/nospec.h>
#include <sound/opl3.h>
#include <sound/asound_fm.h>
@@ -448,7 +449,7 @@ static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * v
{
unsigned short reg_side;
unsigned char op_offset;
- unsigned char voice_offset;
+ unsigned char voice_offset, voice_op;
unsigned short opl3_reg;
unsigned char reg_val;
@@ -473,7 +474,9 @@ static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * v
voice_offset = voice->voice - MAX_OPL2_VOICES;
}
/* Get register offset of operator */
- op_offset = snd_opl3_regmap[voice_offset][voice->op];
+ voice_offset = array_index_nospec(voice_offset, MAX_OPL2_VOICES);
+ voice_op = array_index_nospec(voice->op, 4);
+ op_offset = snd_opl3_regmap[voice_offset][voice_op];
reg_val = 0x00;
/* Set amplitude modulation (tremolo) effect */