netdev - [PATCH nf] netfilter: nf_queue: enqueue skbs with NULL dst

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Message-Id: <20191202185430.31367-1-marco.oliverio@tanaza.com>
Date:   Mon,  2 Dec 2019 19:54:30 +0100
From:   Marco Oliverio <marco.oliverio@...aza.com>
To:     netfilter-devel@...r.kernel.org
Cc:     netdev@...r.kernel.org, fw@...len.de, rocco.folino@...aza.com,
        Marco Oliverio <marco.oliverio@...aza.com>
Subject: [PATCH nf] netfilter: nf_queue: enqueue skbs with NULL dst

Bridge packets that are forwarded have skb->dst == NULL and get
dropped by the check introduced by
b60a77386b1d4868f72f6353d35dabe5fbe981f2 (net: make skb_dst_force
return true when dst is refcounted).

To fix this we check skb_dst() before skb_dst_force(), so we don't
drop skb packet with dst == NULL. This holds also for skb at the
PRE_ROUTING hook so we remove the second check.

Fixes: b60a773 ("net: make skb_dst_forcereturn true when dst is refcounted")

Signed-off-by: Marco Oliverio <marco.oliverio@...aza.com>
Signed-off-by: Rocco Folino <rocco.folino@...aza.com>
---
 net/netfilter/nf_queue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
index a2b58de82600..f8f52ff99cfb 100644
--- a/net/netfilter/nf_queue.c
+++ b/net/netfilter/nf_queue.c
@@ -189,7 +189,7 @@ static int __nf_queue(struct sk_buff *skb, const struct nf_hook_state *state,
 		goto err;
 	}
 
-	if (!skb_dst_force(skb) && state->hook != NF_INET_PRE_ROUTING) {
+	if (skb_dst(skb) && !skb_dst_force(skb)) {
 		status = -ENETDOWN;
 		goto err;
 	}
-- 
2.24.0