[PATCH 6.1 178/481] netfilter: nfnetlink_queue: fix entry leak in bridge verdict error path

Greg Kroah-Hartman
2026-03-23T16:15:01Z

6.1-stable review patch. If anyone has any objections, please let me know.

------------------

From: Hyunwoo Kim <imv4bel@gmail.com>

[ Upstream commit f1ba83755d81c6fc66ac7acd723d238f974091e9 ]

nfqnl_recv_verdict() calls find_dequeue_entry() to remove the queue
entry from the queue data structures, taking ownership of the entry.
For PF_BRIDGE packets, it then calls nfqa_parse_bridge() to parse VLAN
attributes. If nfqa_parse_bridge() returns an error (e.g. NFQA_VLAN
present but NFQA_VLAN_TCI missing), the function returns immediately
without freeing the dequeued entry or its sk_buff.

This leaks the nf_queue_entry, its associated sk_buff, and all held
references (net_device refcounts, struct net refcount). Repeated
triggering exhausts kernel memory.

Fix this by dropping the entry via nfqnl_reinject() with NF_DROP verdict
on the error path, consistent with other error handling in this file.

Fixes: 8d45ff22f1b4 ("netfilter: bridge: nf queue verdict to use NFQA_VLAN and NFQA_L2HDR")
Reviewed-by: David Dull <monderasdor@gmail.com>
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nfnetlink_queue.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index f13eed826cbb8..4e0d1362875bd 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -1262,8 +1262,10 @@ static int nfqnl_recv_verdict(struct sk_buff *skb, const struct nfnl_info *info,

if (entry->state.pf == PF_BRIDGE) {
err = nfqa_parse_bridge(entry, nfqa);
- if (err < 0)
+ if (err < 0) {
+ nfqnl_reinject(entry, NF_DROP);
return err;
+ }
}

if (nfqa[NFQA_PAYLOAD]) {
--
2.51.0