From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denis Efremov Subject: [PATCH v2] bridge: rcu_deref outside read-lock section Date: Tue, 14 Aug 2012 12:08:52 +0400 Message-ID: <1344931732-1858-1-git-send-email-yefremov.denis@gmail.com> References: <1344898062-23633-1-git-send-email-yefremov.denis@gmail.com> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=zuUtXORGIorczT+8QjGCO9egI9kXqP9GhN9mA4Y6ykw=; b=EMbYxkXlaLCTKCFkP8ccFTk2q8u5Kp/sk7UsTEL7RpQUU5Tlo2ZB/2EuSRj7zLfObh iW4zVudRA72MzbiJ66a7lordvdZ7Hv67T8nPNKM3FxcMTKr7OyffM71yk+xVBRHD/NpP rSczwIjlLmtnaBMCCsSuomxMIGZ23RoibYQqMgLWtvSwUQA6Jb9gnKfDOUYwBz/AFkzl 9N42ROBGVWAjjprKFn1PRbbUBRVn6Hqdc19mvCOQDHbjaSM4mAr5gSzMCbfimcXTGhLO dN9aviaoNdkCFZ5yVb8kvpGL8Rq7MstuHLFHHtZiR1Jjeav8Ny549R13PaocqB60eHLN a+Fw== In-Reply-To: <1344898062-23633-1-git-send-email-yefremov.denis@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Stephen Hemminger Cc: Denis Efremov , "David S. Miller" , pablo@netfilter.org, kaber@trash.net, netfilter-devel@vger.kernel.org, netfilter@vger.kernel.org, coreteam@netfilter.org, linux-kernel@vger.kernel.org, ldv-project@ispras.ru As it noted in the comment before the br_handle_frame_finish function, this function should be called under rcu_read_lock. The problem callgraph: br_dev_xmit -> br_nf_pre_routing_finish_bridge_slow -> -> br_handle_frame_finish -> br_port_get_rcu -> rcu_dereference And in this case there is no read-lock section. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Denis Efremov --- net/bridge/br_device.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index 3334845..f9ae07f 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -33,7 +33,9 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) #ifdef CONFIG_BRIDGE_NETFILTER if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) { + rcu_read_lock(); br_nf_pre_routing_finish_bridge_slow(skb); + rcu_read_unlock(); return NETDEV_TX_OK; } #endif -- 1.7.7