[PATCH] netfilter: nf_dup_netdev: Fix net_device reference leak in nft_fwd_dup_netdev_offload()
From: Wentao Liang <hidden>
Date: 2026-09-16 07:37:15
Also in:
lkml, netfilter-devel, stable
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
In nft_fwd_dup_netdev_offload(), dev_get_by_index() gets a reference to
the net_device corresponding to oif. When nft_flow_action_entry_next()
fails (returning NULL), the function returns -E2BIG directly without
dropping the net_device reference via dev_put(), causing a reference
leak.
Add dev_put(dev) before returning -E2BIG on failure.
Fixes: be2861dc36d7 ("netfilter: nft_{fwd,dup}_netdev: add offload support")
Cc: stable@vger.kernel.org
Signed-off-by: Wentao Liang <redacted>
---
net/netfilter/nf_dup_netdev.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_dup_netdev.c b/net/netfilter/nf_dup_netdev.c
index 3b0a70e154cd..dd627b7d72d9 100644
--- a/net/netfilter/nf_dup_netdev.c
+++ b/net/netfilter/nf_dup_netdev.c@@ -80,8 +80,10 @@ int nft_fwd_dup_netdev_offload(struct nft_offload_ctx *ctx, return -EOPNOTSUPP; entry = nft_flow_action_entry_next(ctx, flow); - if (!entry) + if (!entry) { + dev_put(dev); return -E2BIG; + } entry->id = id; entry->dev = dev;
--
2.34.1