diff mbox series

[net,2/4] netfilter: conntrack: fix bug in for_each_sctp_chunk

Message ID 20230124183933.4752-3-pablo@netfilter.org (mailing list archive)
State Accepted
Commit 98ee0077452527f971567db01386de3c3d97ce13
Delegated to: Netdev Maintainers
Headers show
Series [net,1/4] netfilter: conntrack: fix vtag checks for ABORT/SHUTDOWN_COMPLETE | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Pull request is its own cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers fail 3 blamed authors not CCed: acme@mandriva.com laforge@netfilter.org yasuyuki.kozakai@toshiba.co.jp; 6 maintainers not CCed: laforge@netfilter.org acme@mandriva.com coreteam@netfilter.org fw@strlen.de kadlec@netfilter.org yasuyuki.kozakai@toshiba.co.jp
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Pablo Neira Ayuso Jan. 24, 2023, 6:39 p.m. UTC 
From: Sriram Yagnaraman <sriram.yagnaraman@est.tech>

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>
---
 net/netfilter/nf_conntrack_proto_sctp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

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 */