From: Florian Westphal fw@strlen.de
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
--- net/netfilter/ipset/ip_set_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -1639,6 +1639,7 @@ static int ip_set_utest(struct net *net, struct ip_set *set; struct nlattr *tb[IPSET_ATTR_ADT_MAX + 1] = {}; int ret = 0; + u32 lineno;
if (unlikely(protocol_failed(attr) || !attr[IPSET_ATTR_SETNAME] || @@ -1655,7 +1656,7 @@ static int ip_set_utest(struct net *net, 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)