From: Tommi Rantala <tommi.t.rantala@nokia.com> To: netdev@vger.kernel.org Cc: linux-sctp@vger.kernel.org, Neil Horman <nhorman@tuxdriver.com>, Alexey Kodanev <alexey.kodanev@oracle.com>, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>, Tommi Rantala <tommi.t.rantala@nokia.com> Subject: [PATCH net v3] sctp: fix dst refcnt leak in sctp_v4_get_dst Date: Mon, 5 Feb 2018 21:48:14 +0200 [thread overview] Message-ID: <20180205194814.14006-1-tommi.t.rantala@nokia.com> (raw) 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> --- v2: unconditional dst_release() before breaking out of the loop: - if dst == NULL, then dst_release() is no-op. - if dst != &rt->dst, then drop reference to the first dst, we do not need it after all. - if dst == &rt->dst, then the refcnt was incremented twice for this dst, so drop the second ref. net/sctp/protocol.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c index ba28d270eb24..aba2381d3cf9 100644 --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -509,22 +509,20 @@ 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; } -- 2.15.1
WARNING: multiple messages have this Message-ID (diff)
From: Tommi Rantala <tommi.t.rantala@nokia.com> To: netdev@vger.kernel.org Cc: linux-sctp@vger.kernel.org, Neil Horman <nhorman@tuxdriver.com>, Alexey Kodanev <alexey.kodanev@oracle.com>, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>, Tommi Rantala <tommi.t.rantala@nokia.com> Subject: [PATCH net v3] sctp: fix dst refcnt leak in sctp_v4_get_dst Date: Mon, 05 Feb 2018 19:48:14 +0000 [thread overview] Message-ID: <20180205194814.14006-1-tommi.t.rantala@nokia.com> (raw) 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> --- v2: unconditional dst_release() before breaking out of the loop: - if dst = NULL, then dst_release() is no-op. - if dst != &rt->dst, then drop reference to the first dst, we do not need it after all. - if dst = &rt->dst, then the refcnt was incremented twice for this dst, so drop the second ref. net/sctp/protocol.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c index ba28d270eb24..aba2381d3cf9 100644 --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -509,22 +509,20 @@ 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; } -- 2.15.1
next reply other threads:[~2018-02-05 19:49 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-02-05 19:48 Tommi Rantala [this message] 2018-02-05 19:48 ` [PATCH net v3] sctp: fix dst refcnt leak in sctp_v4_get_dst Tommi Rantala 2018-02-05 22:07 ` Marcelo Ricardo Leitner 2018-02-05 22:07 ` Marcelo Ricardo Leitner 2018-02-05 23:20 ` David Ahern 2018-02-05 23:20 ` David Ahern 2018-02-06 5:06 ` Xin Long 2018-02-06 5:06 ` Xin Long 2018-02-06 8:27 ` Dmitry Vyukov 2018-02-06 8:27 ` Dmitry Vyukov 2018-02-06 1:17 ` Neil Horman 2018-02-06 1:17 ` Neil Horman 2018-02-06 2:22 ` David Miller 2018-02-06 2:22 ` David Miller
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20180205194814.14006-1-tommi.t.rantala@nokia.com \ --to=tommi.t.rantala@nokia.com \ --cc=alexey.kodanev@oracle.com \ --cc=linux-sctp@vger.kernel.org \ --cc=marcelo.leitner@gmail.com \ --cc=netdev@vger.kernel.org \ --cc=nhorman@tuxdriver.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.