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>
This commit is contained in:
Kulikov Vasiliy 2010-07-23 06:36:15 +00:00 committed by David S. Miller
parent 50a749c1f2
commit 9c17978089

View file

@ -5796,7 +5796,7 @@ static void s2io_vpd_read(struct s2io_nic *nic)
{
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 @@ static void s2io_vpd_read(struct s2io_nic *nic)
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;
}