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authorTommi Rantala <tommi.t.rantala@nokia.com>2018-02-05 21:48:14 +0200
committerDavid S. Miller <davem@davemloft.net>2018-02-05 21:21:51 -0500
commit4a31a6b19f9ddf498c81f5c9b089742b7472a6f8 (patch)
treef9437936667f550f7135bff2d6fbce0e68eaca2e
parent957d761cf91cdbb175ad7d8f5472336a4d54dbf2 (diff)
sctp: fix dst refcnt leak in sctp_v4_get_dst
Fix dst reference count leak in sctp_v4_get_dst() introduced in commit 410f03831 ("sctp: add routing output fallback"): When walking the address_list, successive ip_route_output_key() calls may return the same rt->dst with the reference incremented on each call. The code would not decrement the dst refcount when the dst pointer was identical from the previous iteration, causing the dst refcnt leak. Testcase: ip netns add TEST ip netns exec TEST ip link set lo up ip link add dummy0 type dummy ip link add dummy1 type dummy ip link add dummy2 type dummy ip link set dev dummy0 netns TEST ip link set dev dummy1 netns TEST ip link set dev dummy2 netns TEST ip netns exec TEST ip addr add 192.168.1.1/24 dev dummy0 ip netns exec TEST ip link set dummy0 up ip netns exec TEST ip addr add 192.168.1.2/24 dev dummy1 ip netns exec TEST ip link set dummy1 up ip netns exec TEST ip addr add 192.168.1.3/24 dev dummy2 ip netns exec TEST ip link set dummy2 up ip netns exec TEST sctp_test -H 192.168.1.2 -P 20002 -h 192.168.1.1 -p 20000 -s -B 192.168.1.3 ip netns del TEST In 4.4 and 4.9 kernels this results to: [ 354.179591] unregister_netdevice: waiting for lo to become free. Usage count = 1 [ 364.419674] unregister_netdevice: waiting for lo to become free. Usage count = 1 [ 374.663664] unregister_netdevice: waiting for lo to become free. Usage count = 1 [ 384.903717] unregister_netdevice: waiting for lo to become free. Usage count = 1 [ 395.143724] unregister_netdevice: waiting for lo to become free. Usage count = 1 [ 405.383645] unregister_netdevice: waiting for lo to become free. Usage count = 1 ... Fixes: 410f03831 ("sctp: add routing output fallback") Fixes: 0ca50d12f ("sctp: fix src address selection if using secondary addresses") Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/sctp/protocol.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 6a38c2503649..91813e686c67 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -514,22 +514,20 @@ static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
if (IS_ERR(rt))
continue;
- if (!dst)
- dst = &rt->dst;
-
/* Ensure the src address belongs to the output
* interface.
*/
odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
false);
if (!odev || odev->ifindex != fl4->flowi4_oif) {
- if (&rt->dst != dst)
+ if (!dst)
+ dst = &rt->dst;
+ else
dst_release(&rt->dst);
continue;
}
- if (dst != &rt->dst)
- dst_release(dst);
+ dst_release(dst);
dst = &rt->dst;
break;
}