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author | Ido Schimmel <idosch@mellanox.com> | 2016-07-22 14:56:20 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-16 09:33:16 +0200 |
commit | 43b90d5fe8694d8cfb2e69a72a190d94e24b0d6f (patch) | |
tree | 212a8cc68c88fdae0cae5b1b434287faea993e8f /net/bridge/br_input.c | |
parent | 053554b934a6b228386c2ff925faaaa51712abed (diff) | |
download | linux-stable-43b90d5fe8694d8cfb2e69a72a190d94e24b0d6f.tar.gz linux-stable-43b90d5fe8694d8cfb2e69a72a190d94e24b0d6f.tar.bz2 linux-stable-43b90d5fe8694d8cfb2e69a72a190d94e24b0d6f.zip |
bridge: Fix incorrect re-injection of LLDP packets
[ 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 <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/bridge/br_input.c')
-rw-r--r-- | net/bridge/br_input.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 160797722228..b32f5a4750bf 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -213,6 +213,16 @@ drop: } EXPORT_SYMBOL_GPL(br_handle_frame_finish); +static void __br_handle_local_finish(struct sk_buff *skb) +{ + struct net_bridge_port *p = br_port_get_rcu(skb->dev); + u16 vid = 0; + + /* check if vlan is allowed, to avoid spoofing */ + if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid)) + br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false); +} + /* note: already called with rcu_read_lock */ static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { @@ -279,6 +289,14 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb) 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; |