diff options
author | Florian Westphal <fw@strlen.de> | 2020-01-09 00:17:13 +0100 |
---|---|---|
committer | Jozsef Kadlecsik <kadlec@netfilter.org> | 2020-01-09 20:16:50 +0100 |
commit | c5a02e144277effbe22c321e1675cbb80a361745 (patch) | |
tree | 3a7d03ff999494c69737290df914f93d30a05916 /kernel/net | |
parent | 5743b3b545fc3b48c53fe3d763fa7ec738af27bf (diff) |
netfilter: ipset: avoid null deref when IPSET_ATTR_LINENO is present
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: Jozsef Kadlecsik <kadlec@netfilter.org>
Diffstat (limited to 'kernel/net')
-rw-r--r-- | kernel/net/netfilter/ipset/ip_set_core.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/net/netfilter/ipset/ip_set_core.c b/kernel/net/netfilter/ipset/ip_set_core.c index 4d8e8b1..e367f3b 100644 --- a/kernel/net/netfilter/ipset/ip_set_core.c +++ b/kernel/net/netfilter/ipset/ip_set_core.c @@ -1871,6 +1871,7 @@ IPSET_CBFN(ip_set_utest, struct net *net, struct sock *ctnl, 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] || @@ -1887,7 +1888,7 @@ IPSET_CBFN(ip_set_utest, struct net *net, struct sock *ctnl, 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) |