skb_header_pointer() will return NULL if offset + sizeof(_sch) exceeds skb->len, so this offset < skb->len test is redundant. if sch->length == 0, this will end up in an infinite loop, add a check for sch->length > 0 Suggested-by: Florian Westphal <fw@xxxxxxxxx> Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@xxxxxxxx> --- net/netfilter/nf_conntrack_proto_sctp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c index 2b2c549ba678..c561c1213704 100644 --- a/net/netfilter/nf_conntrack_proto_sctp.c +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -160,8 +160,8 @@ static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct) #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) \ for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0; \ - (offset) < (skb)->len && \ - ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))); \ + ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))) && \ + (sch)->length; \ (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++) /* Some validity checks to make sure the chunks are fine */ -- 2.34.1
