summaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
authorLiping Zhang <zlpnobody@gmail.com>2017-04-02 18:01:33 +0800
committerPablo Neira Ayuso <pablo@netfilter.org>2017-04-08 23:52:17 +0200
commit207df81501021f6d1a935cebf8e1f34d6d25564b (patch)
treea64275e3cf253dc9e3ec2b6f0bd635651746fa11 /net
parent0c7930e5763bdd189bd50035c025a9cbe5e82f23 (diff)
netfilter: ctnetlink: skip dumping expect when nfct_help(ct) is NULL
For IPCTNL_MSG_EXP_GET, if the CTA_EXPECT_MASTER attr is specified, then the NLM_F_DUMP request will dump the expectations related to this connection tracking. But we forget to check whether the conntrack has nf_conn_help or not, so if nfct_help(ct) is NULL, oops will happen: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: ctnetlink_exp_ct_dump_table+0xf9/0x1e0 [nf_conntrack_netlink] Call Trace: ? ctnetlink_exp_ct_dump_table+0x75/0x1e0 [nf_conntrack_netlink] netlink_dump+0x124/0x2a0 __netlink_dump_start+0x161/0x190 ctnetlink_dump_exp_ct+0x16c/0x1bc [nf_conntrack_netlink] ? ctnetlink_exp_fill_info.constprop.33+0xf0/0xf0 [nf_conntrack_netlink] ? ctnetlink_glue_seqadj+0x20/0x20 [nf_conntrack_netlink] ctnetlink_get_expect+0x32e/0x370 [nf_conntrack_netlink] ? debug_lockdep_rcu_enabled+0x1d/0x20 nfnetlink_rcv_msg+0x60a/0x6a9 [nfnetlink] ? nfnetlink_rcv_msg+0x1b9/0x6a9 [nfnetlink] [...] Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_conntrack_netlink.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index f9c643bc1a8e..f78eadba343d 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -2794,6 +2794,12 @@ static int ctnetlink_dump_exp_ct(struct net *net, struct sock *ctnl,
return -ENOENT;
ct = nf_ct_tuplehash_to_ctrack(h);
+ /* No expectation linked to this connection tracking. */
+ if (!nfct_help(ct)) {
+ nf_ct_put(ct);
+ return 0;
+ }
+
c.data = ct;
err = netlink_dump_start(ctnl, skb, nlh, &c);