From: Florian Westphal <fw@strlen.de>
To: netfilter-devel@vger.kernel.org
Cc: netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com,
Florian Westphal <fw@strlen.de>,
Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>,
syzbot+34bd2369d38707f3f4a7@syzkaller.appspotmail.com
Subject: [PATCH nf] netfilter: ipset: avoid null deref when IPSET_ATTR_LINENO is present
Date: Wed, 8 Jan 2020 10:59:38 +0100 [thread overview]
Message-ID: <20200108095938.3704-1-fw@strlen.de> (raw)
In-Reply-To: <000000000000a347ef059b8ee979@google.com>
The set uadt functions assume lineno is never NULL, but it is in
case of ip_set_utest().
syzkaller managed to generate a netlink message that calls this with
LINENO attr present:
general protection fault: 0000 [#1] PREEMPT SMP KASAN
RIP: 0010:hash_mac4_uadt+0x1bc/0x470 net/netfilter/ipset/ip_set_hash_mac.c:104
Call Trace:
ip_set_utest+0x55b/0x890 net/netfilter/ipset/ip_set_core.c:1867
nfnetlink_rcv_msg+0xcf2/0xfb0 net/netfilter/nfnetlink.c:229
netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
nfnetlink_rcv+0x1ba/0x460 net/netfilter/nfnetlink.c:563
pass a dummy lineno storage, its easier than patching all set
implementations.
This seems to be a day-0 bug.
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Reported-by: syzbot+34bd2369d38707f3f4a7@syzkaller.appspotmail.com
Fixes: a7b4f989a6294 ("netfilter: ipset: IP set core support")
Signed-off-by: Florian Westphal <fw@strlen.de>
---
net/netfilter/ipset/ip_set_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index 169e0a04f814..cf895bc80871 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -1848,6 +1848,7 @@ static int ip_set_utest(struct net *net, struct sock *ctnl, struct sk_buff *skb,
struct ip_set *set;
struct nlattr *tb[IPSET_ATTR_ADT_MAX + 1] = {};
int ret = 0;
+ u32 lineno;
if (unlikely(protocol_min_failed(attr) ||
!attr[IPSET_ATTR_SETNAME] ||
@@ -1864,7 +1865,7 @@ static int ip_set_utest(struct net *net, struct sock *ctnl, struct sk_buff *skb,
return -IPSET_ERR_PROTOCOL;
rcu_read_lock_bh();
- ret = set->variant->uadt(set, tb, IPSET_TEST, NULL, 0, 0);
+ ret = set->variant->uadt(set, tb, IPSET_TEST, &lineno, 0, 0);
rcu_read_unlock_bh();
/* Userspace can't trigger element to be re-added */
if (ret == -EAGAIN)
--
2.24.1
next prev parent reply other threads:[~2020-01-08 10:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-07 16:03 general protection fault in hash_ipportnet4_uadt syzbot
2020-01-07 17:28 ` syzbot
2020-01-08 9:59 ` Florian Westphal [this message]
2020-01-08 10:05 ` [PATCH nf] netfilter: ipset: avoid null deref when IPSET_ATTR_LINENO is present Kadlecsik József
2020-01-08 10:37 ` [PATCH] " Jan Engelhardt
2020-01-08 12:43 ` Kadlecsik József
2020-01-08 22:32 ` [PATCH nf] " Pablo Neira Ayuso
2020-01-08 16:53 ` general protection fault in hash_ipportnet4_uadt syzbot
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