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authorXin Long <lucien.xin@gmail.com>2019-03-13 17:00:48 +0800
committerDavid S. Miller <davem@davemloft.net>2019-03-13 14:22:49 -0700
commit9417d81f4f8adfe20a12dd1fadf73a618cbd945d (patch)
treee5909be0f6b3404f4a85c7bc184aa21b7dc32c45 /drivers
parentMAINTAINERS: GENET & SYSTEMPORT: Add internal Broadcom list (diff)
downloadlinux-dev-9417d81f4f8adfe20a12dd1fadf73a618cbd945d.tar.xz
linux-dev-9417d81f4f8adfe20a12dd1fadf73a618cbd945d.zip
pptp: dst_release sk_dst_cache in pptp_sock_destruct
sk_setup_caps() is called to set sk->sk_dst_cache in pptp_connect, so we have to dst_release(sk->sk_dst_cache) in pptp_sock_destruct, otherwise, the dst refcnt will leak. It can be reproduced by this syz log: r1 = socket$pptp(0x18, 0x1, 0x2) bind$pptp(r1, &(0x7f0000000100)={0x18, 0x2, {0x0, @local}}, 0x1e) connect$pptp(r1, &(0x7f0000000000)={0x18, 0x2, {0x3, @remote}}, 0x1e) Consecutive dmesg warnings will occur: unregister_netdevice: waiting for lo to become free. Usage count = 1 v1->v2: - use rcu_dereference_protected() instead of rcu_dereference_check(), as suggested by Eric. Fixes: 00959ade36ac ("PPTP: PPP over IPv4 (Point-to-Point Tunneling Protocol)") Reported-by: Xiumei Mu <xmu@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/ppp/pptp.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 8f09edd811e9..50c60550f295 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -532,6 +532,7 @@ static void pptp_sock_destruct(struct sock *sk)
pppox_unbind_sock(sk);
}
skb_queue_purge(&sk->sk_receive_queue);
+ dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
}
static int pptp_create(struct net *net, struct socket *sock, int kern)