6.4-stable review patch. If anyone has any objections, please let me know.
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From: Wander Lairson Costa wander@redhat.com
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 wmliang@infosec.exchange Signed-off-by: Wander Lairson Costa wander@redhat.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/xt_sctp.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/net/netfilter/xt_sctp.c +++ b/net/netfilter/xt_sctp.c @@ -149,6 +149,8 @@ static int sctp_mt_check(const struct xt { 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)