From b63b4e114593073a1c25087526782258c9dd5347 Mon Sep 17 00:00:00 2001 From: Wander Lairson Costa Date: Mon, 28 Aug 2023 19:12:55 -0300 Subject: [PATCH] netfilter: xt_sctp: validate the flag_info count commit e99476497687ef9e850748fe6d232264f30bc8f9 upstream. 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 Signed-off-by: Wander Lairson Costa Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/xt_sctp.c | 2 ++ 1 file changed, 2 insertions(+) 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)