[PATCH -stable,4.19.x 14/40] netfilter: nf_tables: GC transaction race with netns dismantle

Pablo Neira Ayuso
2024-06-13T01:02:27Z

commit 02c6c24402bf1c1e986899c14ba22a10b510916b upstream.

Use maybe_get_net() since GC workqueue might race with netns exit path.

Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
---
net/netfilter/nf_tables_api.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 4ac923ec11d6..81bdc5201c91 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6820,9 +6820,14 @@ struct nft_trans_gc *nft_trans_gc_alloc(struct nft_set *set,
if (!trans)
return NULL;

+ trans->net = maybe_get_net(net);
+ if (!trans->net) {
+ kfree(trans);
+ return NULL;
+ }
+
refcount_inc(&set->refs);
trans->set = set;
- trans->net = get_net(net);
trans->seq = gc_seq;

return trans;
--
2.30.2