[PATCH 4.9 008/191] ALSA: isa/wavefront: prevent out of bounds write in ioctl

Sasha Levin
2020-06-29T20:27:34Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 7f0d5053c5a9d23fe5c2d337495a9d79038d267b ]

The "header->number" comes from the ioctl and it needs to be clamped to
prevent out of bounds writes.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200501094011.GA960082@mwanda
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/isa/wavefront/wavefront_synth.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/sound/isa/wavefront/wavefront_synth.c b/sound/isa/wavefront/wavefront_synth.c
index 718d5e3b7806f..6c06d06457796 100644
--- a/sound/isa/wavefront/wavefront_synth.c
+++ b/sound/isa/wavefront/wavefront_synth.c
@@ -1174,7 +1174,10 @@ wavefront_send_alias (snd_wavefront_t *dev, wavefront_patch_info *header)
"alias for %d\n",
header->number,
header->hdr.a.OriginalSample);
-
+
+ if (header->number >= WF_MAX_SAMPLE)
+ return -EINVAL;
+
munge_int32 (header->number, &alias_hdr[0], 2);
munge_int32 (header->hdr.a.OriginalSample, &alias_hdr[2], 2);
munge_int32 (*((unsigned int *)&header->hdr.a.sampleStartOffset),
@@ -1205,6 +1208,9 @@ wavefront_send_multisample (snd_wavefront_t *dev, wavefront_patch_info *header)
int num_samples;
unsigned char *msample_hdr;

+ if (header->number >= WF_MAX_SAMPLE)
+ return -EINVAL;
+
msample_hdr = kmalloc(WF_MSAMPLE_BYTES, GFP_KERNEL);
if (! msample_hdr)
return -ENOMEM;
--
2.25.1