From: Florian Westphal Date: Thu, 20 Sep 2018 21:53:06 +0000 (+0200) Subject: netfilter: ctnetlink: must check mark attributes vs NULL X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=9306425b70bf1284a037b7461222887aff48cf8d;p=openwrt%2Fstaging%2Fblogic.git netfilter: ctnetlink: must check mark attributes vs NULL else we will oops (null deref) when the attributes aren't present. Also add back the EOPNOTSUPP in case MARK filtering is requested but kernel doesn't support it. Fixes: 59c08c69c2788 ("netfilter: ctnetlink: Support L3 protocol-filter on flush") Reported-by: syzbot+e45eda8eda6e93a03959@syzkaller.appspotmail.com Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 099a450e26be..4ae8e528943a 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -832,6 +832,11 @@ ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family) { struct ctnetlink_filter *filter; +#ifndef CONFIG_NF_CONNTRACK_MARK + if (cda[CTA_MARK] && cda[CTA_MARK_MASK]) + return ERR_PTR(-EOPNOTSUPP); +#endif + filter = kzalloc(sizeof(*filter), GFP_KERNEL); if (filter == NULL) return ERR_PTR(-ENOMEM); @@ -839,8 +844,10 @@ ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family) filter->family = family; #ifdef CONFIG_NF_CONNTRACK_MARK - filter->mark.val = ntohl(nla_get_be32(cda[CTA_MARK])); - filter->mark.mask = ntohl(nla_get_be32(cda[CTA_MARK_MASK])); + if (cda[CTA_MARK] && cda[CTA_MARK_MASK]) { + filter->mark.val = ntohl(nla_get_be32(cda[CTA_MARK])); + filter->mark.mask = ntohl(nla_get_be32(cda[CTA_MARK_MASK])); + } #endif return filter; }