qeth: avoid buffer overflow in snmp ioctl

Check user-defined length in snmp ioctl request and allow request
only if it fits into a qeth command buffer.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Reviewed-by: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Reported-by: Nico Golde <nico@ngolde.de>
Reported-by: Fabian Yamaguchi <fabs@goesec.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ursula Braun 2013-11-06 09:04:52 +01:00 committed by David S. Miller
parent 17102f8be4
commit 6fb392b1a6

View File

@ -4451,7 +4451,7 @@ int qeth_snmp_command(struct qeth_card *card, char __user *udata)
struct qeth_cmd_buffer *iob;
struct qeth_ipa_cmd *cmd;
struct qeth_snmp_ureq *ureq;
int req_len;
unsigned int req_len;
struct qeth_arp_query_info qinfo = {0, };
int rc = 0;
@ -4467,6 +4467,10 @@ int qeth_snmp_command(struct qeth_card *card, char __user *udata)
/* skip 4 bytes (data_len struct member) to get req_len */
if (copy_from_user(&req_len, udata + sizeof(int), sizeof(int)))
return -EFAULT;
if (req_len > (QETH_BUFSIZE - IPA_PDU_HEADER_SIZE -
sizeof(struct qeth_ipacmd_hdr) -
sizeof(struct qeth_ipacmd_setadpparms_hdr)))
return -EINVAL;
ureq = memdup_user(udata, req_len + sizeof(struct qeth_snmp_ureq_hdr));
if (IS_ERR(ureq)) {
QETH_CARD_TEXT(card, 2, "snmpnome");