Commit e9947649 authored by Wander Lairson Costa's avatar Wander Lairson Costa Committed by Pablo Neira Ayuso
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netfilter: xt_sctp: validate the flag_info count 



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: 2e4e6a17 ("[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables")
Cc: stable@vger.kernel.org
Reported-by: default avatarLucas Leong <wmliang@infosec.exchange>
Signed-off-by: default avatarWander Lairson Costa <wander@redhat.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 28427f36

net/netfilter/xt_sctp.c

+2 −0
Original line number Diff line number Diff line
@@ -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)