diff options
| author | Florian Westphal <fw@strlen.de> | 2020-01-08 12:59:38 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-14 22:08:39 +0300 |
| commit | f58642c1bc7946c315d8617d61916f754d90583f (patch) | |
| tree | ace2250da3b1b1d3a23351109854f1ba61e8ca7f /net/netfilter | |
| parent | 99a55d8a7fa4c788afc74d6e5ded8903d1712d1a (diff) | |
| download | linux-f58642c1bc7946c315d8617d61916f754d90583f.tar.xz | |
netfilter: ipset: avoid null deref when IPSET_ATTR_LINENO is present
commit 22dad713b8a5ff488e07b821195270672f486eb2 upstream.
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>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/ipset/ip_set_core.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c index d73d1828216a..d8143a8c034d 100644 --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -1658,6 +1658,7 @@ 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] || @@ -1674,7 +1675,7 @@ 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) |