diff mbox series

[net,2/5] netfilter: xt_sctp: validate the flag_info count

Message ID 20230830235935.465690-3-pablo@netfilter.org
State Accepted
Delegated to: Pablo Neira
Headers show
Series [net,1/5] netfilter: nft_exthdr: Fix non-linear header modification | expand

Commit Message

Pablo Neira Ayuso Aug. 30, 2023, 11:59 p.m. UTC 
From: Wander Lairson Costa <wander@redhat.com>

sctp_mt_check doesn't validate the flag_count field. An attacker can
take advantage of that to trigger a OOB read and leak memory
information.

Add the field validation in the checkentry function.

Fixes: 2e4e6a17af35 ("[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables")
Cc: stable@vger.kernel.org
Reported-by: Lucas Leong <wmliang@infosec.exchange>
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/xt_sctp.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/net/netfilter/xt_sctp.c b/net/netfilter/xt_sctp.c
index e8961094a282..b46a6a512058 100644
--- a/net/netfilter/xt_sctp.c
+++ b/net/netfilter/xt_sctp.c
@@ -149,6 +149,8 @@  static int sctp_mt_check(const struct xt_mtchk_param *par)
 {
 	const struct xt_sctp_info *info = par->matchinfo;
 
+	if (info->flag_count > ARRAY_SIZE(info->flag_info))
+		return -EINVAL;
 	if (info->flags & ~XT_SCTP_VALID_FLAGS)
 		return -EINVAL;
 	if (info->invflags & ~XT_SCTP_VALID_FLAGS)