1 files changed, 5 insertions, 0 deletions

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index 6ea4b22ff28d..468c6003b4c7 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -362,6 +362,11 @@ static int nfattr_to_tcp(struct nfattr *cda[], struct ip_conntrack *ct)
         struct nfattr *attr = cda[CTA_PROTOINFO_TCP-1];
         struct nfattr *tb[CTA_PROTOINFO_TCP_MAX];
 
+        /* updates could not contain anything about the private
+         * protocol info, in that case skip the parsing */
+        if (!attr)
+                return 0;
+
         nfattr_parse_nested(tb, CTA_PROTOINFO_TCP_MAX, attr);
 
         if (!tb[CTA_PROTOINFO_TCP_STATE-1])