ipv6: sr: fix out-of-bounds access in SRH validation

This patch fixes an out-of-bounds access in seg6_validate_srh() when the trailing data is less than sizeof(struct sr6_tlv). Reported-by: Andrey Konovalov <[email protected]> Cc: Andrey Konovalov <[email protected]> Signed-off-by: David Lebrun <[email protected]> Signed-off-by: David S. Miller <[email protected]>
ambv · Apr 20, 2017 · 2f3bb64 · 2f3bb64
1 parent c1f8d0f
commit 2f3bb64
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
@@ -53,6 +53,9 @@ bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len)
 		struct sr6_tlv *tlv;
 		unsigned int tlv_len;
 
+		if (trailing < sizeof(*tlv))
+			return false;
+
 		tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset);
 		tlv_len = sizeof(*tlv) + tlv->len;