[media] rc: ir-lirc-codec: fix potential integer overflow
'n' may be bigger than MAX_INT*sizeof(int), if so checking of truncated
(int)(n/sizeof(int)) for LIRCBUF_SIZE overflow and then using nontruncated 'count'
doesn't make sense. Also n may be up to sizeof(int)-1 bytes bigger than expected,
so check value of (n % sizeof(int)) too.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/rc/ir-lirc-codec.c b/drivers/media/rc/ir-lirc-codec.c
index 1e87ee8..f011c5d 100644
--- a/drivers/media/rc/ir-lirc-codec.c
+++ b/drivers/media/rc/ir-lirc-codec.c
@@ -100,7 +100,8 @@
struct lirc_codec *lirc;
struct rc_dev *dev;
int *txbuf; /* buffer with values to transmit */
- int ret = 0, count;
+ int ret = 0;
+ size_t count;
lirc = lirc_get_pdata(file);
if (!lirc)
@@ -110,7 +111,7 @@
return -EINVAL;
count = n / sizeof(int);
- if (count > LIRCBUF_SIZE || count % 2 == 0)
+ if (count > LIRCBUF_SIZE || count % 2 == 0 || n % sizeof(int) != 0)
return -EINVAL;
txbuf = memdup_user(buf, n);