Commit 9c179780 authored by Kulikov Vasiliy's avatar Kulikov Vasiliy Committed by David S. Miller
Browse files

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: default avatarKulikov Vasiliy <segooon@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 50a749c1

drivers/net/s2io.c

+18 −10
Original line number Diff line number Diff line
@@ -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]);

			    (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;

}

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