From 367e198805de5027da779ab86cebd4a2c69c75d8 Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Tue, 8 Mar 2016 20:29:10 +0100 Subject: netfilter: ipset: Check IPSET_ATTR_ETHER netlink attribute length Julia Lawall pointed out that IPSET_ATTR_ETHER netlink attribute length was not checked explicitly, just for the maximum possible size. Malicious netlink clients could send shorter attribute and thus resulting a kernel read after the buffer. The patch adds the explicit length checkings. Reported-by: Julia Lawall Signed-off-by: Jozsef Kadlecsik --- kernel/net/netfilter/ipset/ip_set_bitmap_ipmac.c | 2 ++ kernel/net/netfilter/ipset/ip_set_hash_mac.c | 3 ++- 2 files changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel/net') diff --git a/kernel/net/netfilter/ipset/ip_set_bitmap_ipmac.c b/kernel/net/netfilter/ipset/ip_set_bitmap_ipmac.c index 0f1cf29..8eea41c 100644 --- a/kernel/net/netfilter/ipset/ip_set_bitmap_ipmac.c +++ b/kernel/net/netfilter/ipset/ip_set_bitmap_ipmac.c @@ -267,6 +267,8 @@ bitmap_ipmac_uadt(struct ip_set *set, struct nlattr *tb[], e.id = ip_to_id(map, ip); if (tb[IPSET_ATTR_ETHER]) { + if (nla_len(tb[IPSET_ATTR_ETHER]) != ETH_ALEN) + return -IPSET_ERR_PROTOCOL; memcpy(e.ether, nla_data(tb[IPSET_ATTR_ETHER]), ETH_ALEN); e.add_mac = 1; } diff --git a/kernel/net/netfilter/ipset/ip_set_hash_mac.c b/kernel/net/netfilter/ipset/ip_set_hash_mac.c index f1e7d2c..8f004ed 100644 --- a/kernel/net/netfilter/ipset/ip_set_hash_mac.c +++ b/kernel/net/netfilter/ipset/ip_set_hash_mac.c @@ -110,7 +110,8 @@ hash_mac4_uadt(struct ip_set *set, struct nlattr *tb[], if (tb[IPSET_ATTR_LINENO]) *lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]); - if (unlikely(!tb[IPSET_ATTR_ETHER])) + if (unlikely(!tb[IPSET_ATTR_ETHER] || + nla_len(tb[IPSET_ATTR_ETHER]) != ETH_ALEN)) return -IPSET_ERR_PROTOCOL; ret = ip_set_get_extensions(set, tb, &ext); -- cgit v1.2.3