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| author | Ido Schimmel <idosch@mellanox.com> | 2016-07-22 14:56:20 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-16 09:34:57 +0200 |
| commit | 5986b7b7284dbb5a3ea117c36608b19504b862a5 (patch) | |
| tree | 6829a474b7ca1e64129428eca2a41f78e977e60f /net | |
| parent | 746ac22c5abcb497611aa6435964a78b8928e70f (diff) | |
| download | lwn-5986b7b7284dbb5a3ea117c36608b19504b862a5.tar.gz lwn-5986b7b7284dbb5a3ea117c36608b19504b862a5.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')
| -rw-r--r-- | net/bridge/br_input.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 43d2cd862bc2..28d5ec269e48 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -288,6 +288,14 @@ 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; |