From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ido Schimmel , Jiri Pirko , Florian Westphal , John Fastabend , "David S. Miller" Subject: [PATCH 4.7 06/41] bridge: Fix incorrect re-injection of LLDP packets Date: Sun, 14 Aug 2016 22:38:32 +0200 Message-Id: <20160814202532.446801110@linuxfoundation.org> In-Reply-To: <20160814202531.818402015@linuxfoundation.org> References: <20160814202531.818402015@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ido Schimmel [ Upstream commit baedbe55884c003819f5c8c063ec3d2569414296 ] Commit 8626c56c8279 ("bridge: fix potential use-after-free when hook returns QUEUE or STOLEN verdict") caused LLDP packets arriving through a bridge port to be re-injected to the Rx path with skb->dev set to the bridge device, but this breaks the lldpad daemon. The lldpad daemon opens a packet socket with protocol set to ETH_P_LLDP for any valid device on the system, which doesn't not include soft devices such as bridge and VLAN. Since packet sockets (ptype_base) are processed in the Rx path after the Rx handler, LLDP packets with skb->dev set to the bridge device never reach the lldpad daemon. Fix this by making the bridge's Rx handler re-inject LLDP packets with RX_HANDLER_PASS, which effectively restores the behaviour prior to the mentioned commit. This means netfilter will never receive LLDP packets coming through a bridge port, as I don't see a way in which we can have okfn() consume the packet without breaking existing behaviour. I've already carried out a similar fix for STP packets in commit 56fae404fb2c ("bridge: Fix incorrect re-injection of STP packets"). Fixes: 8626c56c8279 ("bridge: fix potential use-after-free when hook returns QUEUE or STOLEN verdict") Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Cc: Florian Westphal Cc: John Fastabend Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/bridge/br_input.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -288,6 +288,14 @@ rx_handler_result_t br_handle_frame(stru case 0x01: /* IEEE MAC (Pause) */ goto drop; + case 0x0E: /* 802.1AB LLDP */ + fwd_mask |= p->br->group_fwd_mask; + if (fwd_mask & (1u << dest[5])) + goto forward; + *pskb = skb; + __br_handle_local_finish(skb); + return RX_HANDLER_PASS; + default: /* Allow selective forwarding for most other protocols */ fwd_mask |= p->br->group_fwd_mask;