2019-05-13 19:48:03

by Jagdish Motwani

Subject: [PATCH net v3] netfilter: nf_queue:fix reinject verdict handling

From: Jagdish Motwani <[email protected]>

This patch fixes netfilter hook traversal when there are more than 1 hooks
returning NF_QUEUE verdict. When the first queue reinjects the packet,
'nf_reinject' starts traversing hooks with a proper hook_index. However,
if it again receives a NF_QUEUE verdict (by some other netfilter hook), it
queues the packet with a wrong hook_index. So, when the second queue
reinjects the packet, it re-executes hooks in between.

Fixes: 960632ece694 ("netfilter: convert hook list to an array")
Signed-off-by: Jagdish Motwani <[email protected]>
---
net/netfilter/nf_queue.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
index 9dc1d6e..b5b2be5 100644
--- a/net/netfilter/nf_queue.c
+++ b/net/netfilter/nf_queue.c
@@ -255,6 +255,7 @@ static unsigned int nf_iterate(struct sk_buff *skb,
repeat:
verdict = nf_hook_entry_hookfn(hook, skb, state);
if (verdict != NF_ACCEPT) {
+ *index = i;
if (verdict != NF_REPEAT)
return verdict;
goto repeat;
--
2.9.5

2019-05-21 14:04:39

by Pablo Neira Ayuso

Subject: Re: [PATCH net v3] netfilter: nf_queue:fix reinject verdict handling

On Mon, May 13, 2019 at 11:47:40PM +0530, Jagdish Motwani wrote:
> From: Jagdish Motwani <[email protected]>
>
> This patch fixes netfilter hook traversal when there are more than 1 hooks
> returning NF_QUEUE verdict. When the first queue reinjects the packet,
> 'nf_reinject' starts traversing hooks with a proper hook_index. However,
> if it again receives a NF_QUEUE verdict (by some other netfilter hook), it
> queues the packet with a wrong hook_index. So, when the second queue
> reinjects the packet, it re-executes hooks in between.

Applied, thanks.