[PATCH 3.5 62/78] qeth: avoid buffer overflow in snmp ioctl

Luis Henriques luis.henriques at canonical.com
Mon Nov 25 13:06:49 UTC 2013


3.5.7.26 -stable review patch.  If anyone has any objections, please let me know.

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

From: Ursula Braun <ursula.braun at de.ibm.com>

commit 6fb392b1a63ae36c31f62bc3fc8630b49d602b62 upstream.

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 at de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka at de.ibm.com>
Reviewed-by: Heiko Carstens <heicars2 at linux.vnet.ibm.com>
Reported-by: Nico Golde <nico at ngolde.de>
Reported-by: Fabian Yamaguchi <fabs at goesec.de>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/s390/net/qeth_core_main.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index e118e1e..c3121f7 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -4355,7 +4355,7 @@ 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;
 
@@ -4371,6 +4371,10 @@ 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");
-- 
1.8.3.2





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