Commit 98ee0077 authored by Sriram Yagnaraman's avatar Sriram Yagnaraman Committed by Pablo Neira Ayuso
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netfilter: conntrack: fix bug in for_each_sctp_chunk 



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: 9fb9cbb1 ("[NETFILTER]: Add nf_conntrack subsystem.")
Suggested-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarSriram Yagnaraman <sriram.yagnaraman@est.tech>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent a9993591

net/netfilter/nf_conntrack_proto_sctp.c

+2 −2
Original line number Diff line number Diff line
@@ -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 */