[media] si2168: Bounds check firmware
When reading the firmware and sending commands, the length must
be bounds checked to avoid overrunning the size of the command
buffer and smashing the stack if the firmware is not in the expected
format:
si2168 11-0064: found a 'Silicon Labs Si2168-B40'
si2168 11-0064: downloading firmware from file 'dvb-demod-si2168-b40-01.fw'
si2168 11-0064: firmware download failed -95
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffffa085708f
Add the proper check.
Cc: stable@kernel.org
Reported-by: Stuart Auchterlonie <sauchter@redhat.com>
Reviewed-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c
index 81788c5..821a8f4 100644
--- a/drivers/media/dvb-frontends/si2168.c
+++ b/drivers/media/dvb-frontends/si2168.c
@@ -502,6 +502,10 @@
/* firmware is in the new format */
for (remaining = fw->size; remaining > 0; remaining -= 17) {
len = fw->data[fw->size - remaining];
+ if (len > SI2168_ARGLEN) {
+ ret = -EINVAL;
+ break;
+ }
memcpy(cmd.args, &fw->data[(fw->size - remaining) + 1], len);
cmd.wlen = len;
cmd.rlen = 1;