From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELvrY+qhvv0HE9I4yseHHAspGUDyIhXDXj4EIZASWF/a3q7RGTFxJFmWtZOaKKUtnm0HUg3W ARC-Seal: i=1; a=rsa-sha256; t=1520641241; cv=none; d=google.com; s=arc-20160816; b=jRkjA4avdPWnT4ttFoLh5sRG0zMDYj3K8nEXYEVqt+4fwO7dvq82tA76EvPQxVH2Yg nUE1OAAdlIvxWB/HYdJDHjadWFYNTDCzjrnFumw5b1J9EbSLO9ofNR0G6zY/VQRGDqWP oOrdd+0GqyBWe+GlKlQ14wSP5ddheBzyxivpfJ9urUrU00j1r5TZq/vwEV4Zwl6+arNH fNC9mA94abvegxEp4Fqfgzhy2JQcFuWz5gFEF+/CeivjJ3mmZlvcok7mqwofu+sJ+jDx vw+Xbk3oIfTQQGmF7BxzD8J9q2wunATqWwc6UgEJ5YLBXxlY3j30d0cLc7oqgbm0Wty4 bV/w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=5DoQitcmezpp+dQ9fa9Bzd+k8zDELxoCUPiZ+/0RNw8=; b=WbU19Wyac5shzE7nWf/Y7Xojkfp4SYu421hISfLobv2+vqm9SzKo4i5lgDVBFf7FsS ELhMHBl26XmzmOwDKHusEDHNmMEDsVH6SFfgyXzlKuBNhfVv7C4oBGpY6dexSFHDKMfK EgCM42S7oL0e1h9BTxG3WTzGDB44Ievi1AfTl8mX+Go8nLtLmYX5KHXyPucLHP2JSgdV dROMrm4+hD2jO+VvKak0kJZzAou1Yvq0h/NxzGBgWtipuKE1kP7kR4XdN9zRjw0efBzK AFtAmXpwsq0DHbhEZ7ixxojzdCUurq6Lw3Tt4Tq2n24+Ueftp4wv1oH+LsFZN+448JlL ntbA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 185.236.200.248 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 185.236.200.248 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tommi Rantala , Marcelo Ricardo Leitner , Neil Horman , "David S. Miller" Subject: [PATCH 4.4 27/36] sctp: fix dst refcnt leak in sctp_v4_get_dst Date: Fri, 9 Mar 2018 16:18:43 -0800 Message-Id: <20180310001808.854479450@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180310001807.213987241@linuxfoundation.org> References: <20180310001807.213987241@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1594507910260968462?= X-GMAIL-MSGID: =?utf-8?q?1594507910260968462?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tommi Rantala [ Upstream commit 4a31a6b19f9ddf498c81f5c9b089742b7472a6f8 ] 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 Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sctp/protocol.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -508,22 +508,20 @@ static void sctp_v4_get_dst(struct sctp_ 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; }