[PATCH 5.16 068/126] netfilter: nft_reject_bridge: Fix for missing reply from prerouting

Greg Kroah-Hartman
2022-02-07T11:59:26Z

From: Phil Sutter <phil@nwl.cc>

commit aeac4554eb549037ff2f719200c0a9c1c25e7eaa upstream.

Prior to commit fa538f7cf05aa ("netfilter: nf_reject: add reject skbuff
creation helpers"), nft_reject_bridge did not assign to nskb->dev before
passing nskb on to br_forward(). The shared skbuff creation helpers
introduced in above commit do which seems to confuse br_forward() as
reject statements in prerouting hook won't emit a packet anymore.

Fix this by simply passing NULL instead of 'dev' to the helpers - they
use the pointer for just that assignment, nothing else.

Fixes: fa538f7cf05aa ("netfilter: nf_reject: add reject skbuff creation helpers")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bridge/netfilter/nft_reject_bridge.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/net/bridge/netfilter/nft_reject_bridge.c
+++ b/net/bridge/netfilter/nft_reject_bridge.c
@@ -49,7 +49,7 @@ static void nft_reject_br_send_v4_tcp_re
{
struct sk_buff *nskb;

- nskb = nf_reject_skb_v4_tcp_reset(net, oldskb, dev, hook);
+ nskb = nf_reject_skb_v4_tcp_reset(net, oldskb, NULL, hook);
if (!nskb)
return;

@@ -65,7 +65,7 @@ static void nft_reject_br_send_v4_unreac
{
struct sk_buff *nskb;

- nskb = nf_reject_skb_v4_unreach(net, oldskb, dev, hook, code);
+ nskb = nf_reject_skb_v4_unreach(net, oldskb, NULL, hook, code);
if (!nskb)
return;

@@ -81,7 +81,7 @@ static void nft_reject_br_send_v6_tcp_re
{
struct sk_buff *nskb;

- nskb = nf_reject_skb_v6_tcp_reset(net, oldskb, dev, hook);
+ nskb = nf_reject_skb_v6_tcp_reset(net, oldskb, NULL, hook);
if (!nskb)
return;

@@ -98,7 +98,7 @@ static void nft_reject_br_send_v6_unreac
{
struct sk_buff *nskb;

- nskb = nf_reject_skb_v6_unreach(net, oldskb, dev, hook, code);
+ nskb = nf_reject_skb_v6_unreach(net, oldskb, NULL, hook, code);
if (!nskb)
return;