From: Sriram Yagnaraman sriram.yagnaraman@est.tech
[ Upstream commit 98ee0077452527f971567db01386de3c3d97ce13 ]
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
Fixes: 9fb9cbb1082d ("[NETFILTER]: Add nf_conntrack subsystem.") Suggested-by: Florian Westphal fw@strlen.de Signed-off-by: Sriram Yagnaraman sriram.yagnaraman@est.tech Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 3704d1c7d3c2..ee317f9a22e5 100644 --- a/net/netfilter/nf_conntrack_proto_sctp.c +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -155,8 +155,8 @@ 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 */