[PATCH 3.16 01/99] wireless: airo: potential buffer overflow in sprintf()

From: Ben Hutchings
Date: Tue Apr 02 2019 - 09:48:14 EST


3.16.65-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 3d39e1bb1c88f32820c5f9271f2c8c2fb9a52bac upstream.

It looks like we wanted to print a maximum of BSSList_rid.ssidLen bytes
of the ssid, but we accidentally use "%*s" (width) instead of "%.*s"
(precision) so if the ssid doesn't have a NUL terminator this could lead
to an overflow.

Static analysis. Not tested.

Fixes: e174961ca1a0 ("net: convert print_mac to %pM")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/net/wireless/airo.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/wireless/airo.c
+++ b/drivers/net/wireless/airo.c
@@ -5469,7 +5469,7 @@ static int proc_BSSList_open( struct ino
we have to add a spin lock... */
rc = readBSSListRid(ai, doLoseSync, &BSSList_rid);
while(rc == 0 && BSSList_rid.index != cpu_to_le16(0xffff)) {
- ptr += sprintf(ptr, "%pM %*s rssi = %d",
+ ptr += sprintf(ptr, "%pM %.*s rssi = %d",
BSSList_rid.bssid,
(int)BSSList_rid.ssidLen,
BSSList_rid.ssid,