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authorGuillaume Nault <g.nault@alphalink.fr>2017-03-29 08:44:59 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-05-03 08:36:35 -0700
commit59bc404b382967a41250cc01299b0419e61392c0 (patch)
tree2f3d778a13c04e71c33622fad69cd07cdb4c2faf
parent501299e643814d2367aeeae8439129f0facc4183 (diff)
l2tp: hold tunnel socket when handling control frames in l2tp_ip and l2tp_ip6
[ Upstream commit 94d7ee0baa8b764cf64ad91ed69464c1a6a0066b ] The code following l2tp_tunnel_find() expects that a new reference is held on sk. Either sk_receive_skb() or the discard_put error path will drop a reference from the tunnel's socket. This issue exists in both l2tp_ip and l2tp_ip6. Fixes: a3c18422a4b4 ("l2tp: hold socket before dropping lock in l2tp_ip{, 6}_recv()") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/l2tp/l2tp_ip.c5
-rw-r--r--net/l2tp/l2tp_ip6.c5
2 files changed, 6 insertions, 4 deletions
diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c
index ff750bb334fa..20669537816e 100644
--- a/net/l2tp/l2tp_ip.c
+++ b/net/l2tp/l2tp_ip.c
@@ -178,9 +178,10 @@ pass_up:
tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
tunnel = l2tp_tunnel_find(net, tunnel_id);
- if (tunnel != NULL)
+ if (tunnel) {
sk = tunnel->sock;
- else {
+ sock_hold(sk);
+ } else {
struct iphdr *iph = (struct iphdr *) skb_network_header(skb);
read_lock_bh(&l2tp_ip_lock);
diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c
index 1a65c9a517b6..a4b0c9232bf1 100644
--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -191,9 +191,10 @@ pass_up:
tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
tunnel = l2tp_tunnel_find(net, tunnel_id);
- if (tunnel != NULL)
+ if (tunnel) {
sk = tunnel->sock;
- else {
+ sock_hold(sk);
+ } else {
struct ipv6hdr *iph = ipv6_hdr(skb);
read_lock_bh(&l2tp_ip6_lock);