net: s2io: fix buffer overflow
vpd_data[] is allocated as kmalloc(256, GFP_KERNEL), so if cnt = 255
then (cnt + 3) overflows 256. memset() is executed without checking.
vpd_data[cnt+2] must be less than 256-cnt-2 as the latter is number of
vpd_data[] elements to copy.
Do not fill with zero the beginning of nic->serial_num as it will
be filled with vpd_data[].
String in product_name[] should be terminated by '\0'.
Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index b8b8584..18bc5b7 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -5796,7 +5796,7 @@
{
u8 *vpd_data;
u8 data;
- int i = 0, cnt, fail = 0;
+ int i = 0, cnt, len, fail = 0;
int vpd_addr = 0x80;
struct swStat *swstats = &nic->mac_control.stats_info->sw_stat;
@@ -5837,20 +5837,28 @@
if (!fail) {
/* read serial number of adapter */
- for (cnt = 0; cnt < 256; cnt++) {
+ for (cnt = 0; cnt < 252; cnt++) {
if ((vpd_data[cnt] == 'S') &&
- (vpd_data[cnt+1] == 'N') &&
- (vpd_data[cnt+2] < VPD_STRING_LEN)) {
- memset(nic->serial_num, 0, VPD_STRING_LEN);
- memcpy(nic->serial_num, &vpd_data[cnt + 3],
- vpd_data[cnt+2]);
- break;
+ (vpd_data[cnt+1] == 'N')) {
+ len = vpd_data[cnt+2];
+ if (len < min(VPD_STRING_LEN, 256-cnt-2)) {
+ memcpy(nic->serial_num,
+ &vpd_data[cnt + 3],
+ len);
+ memset(nic->serial_num+len,
+ 0,
+ VPD_STRING_LEN-len);
+ break;
+ }
}
}
}
- if ((!fail) && (vpd_data[1] < VPD_STRING_LEN))
- memcpy(nic->product_name, &vpd_data[3], vpd_data[1]);
+ if ((!fail) && (vpd_data[1] < VPD_STRING_LEN)) {
+ len = vpd_data[1];
+ memcpy(nic->product_name, &vpd_data[3], len);
+ nic->product_name[len] = 0;
+ }
kfree(vpd_data);
swstats->mem_freed += 256;
}
