This is a note to let you know that I've just added the patch titled
netfilter: conntrack: fix bug in for_each_sctp_chunk
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netfilter-conntrack-fix-bug-in-for_each_sctp_chunk.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 95321a183d8e02fdb31af7bdbb6a006a9b9c98b0
Author: Sriram Yagnaraman <sriram.yagnaraman@xxxxxxxx>
Date: Tue Jan 24 02:47:19 2023 +0100
netfilter: conntrack: fix bug in for_each_sctp_chunk
[ 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@xxxxxxxxx>
Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@xxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 */
