Commit 8626c56c8279 ("bridge: fix potential use-after-free when hook
returns QUEUE or STOLEN verdict") fixed incorrect usage of NF_HOOK's
return value by consuming packets in okfn via br_pass_frame_up().
However, this function re-injects packets to the Rx path with skb->dev
set to the bridge device, which breaks kernel's STP, as all STP packets
appear to originate from the bridge device itself.
Instead, if okfn was called for a packet, make bridge's rx_handler
re-inject it to the Rx path by returning RX_HANDLER_PASS. This is
consistent with previous behavior.
Cc: Florian Westphal <fw@xxxxxxxxx>
Fixes: 8626c56c8279 ("bridge: fix potential use-after-free when hook returns QUEUE or STOLEN verdict")
Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxxxx>
Signed-off-by: Ido Schimmel <idosch@xxxxxxxxxxxx>
---
net/bridge/br_input.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 1607977..c73ed44 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -223,9 +223,7 @@ static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_bu
if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid))
br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false);
- BR_INPUT_SKB_CB(skb)->brdev = p->br->dev;
- br_pass_frame_up(skb);
- return 0;
+ return RX_HANDLER_PASS;
}
/*
@@ -238,6 +236,7 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
struct sk_buff *skb = *pskb;
const unsigned char *dest = eth_hdr(skb)->h_dest;
br_should_route_hook_t *rhook;
+ int err;
if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
return RX_HANDLER_PASS;
@@ -287,8 +286,11 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
}
/* Deliver packet to local host only */
- NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, dev_net(skb->dev),
- NULL, skb, skb->dev, NULL, br_handle_local_finish);
+ err = NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, dev_net(skb->dev),
+ NULL, skb, skb->dev, NULL,
+ br_handle_local_finish);
+ if (err == RX_HANDLER_PASS)
+ return RX_HANDLER_PASS;
return RX_HANDLER_CONSUMED;
}
--
2.4.3
