This is a note to let you know that I've just added the patch titled
netfilter: nf_tables: flush pending destroy work before netlink notifier
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netfilter-nf_tables-flush-pending-destroy-work-befor.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a0227f3bd4faa1bff72b7b65e1c309cfc3fb4088
Author: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Date: Fri Aug 18 01:13:31 2023 +0200
netfilter: nf_tables: flush pending destroy work before netlink notifier
[ Upstream commit 2c9f0293280e258606e54ed2b96fa71498432eae ]
Destroy work waits for the RCU grace period then it releases the objects
with no mutex held. All releases objects follow this path for
transactions, therefore, order is guaranteed and references to top-level
objects in the hierarchy remain valid.
However, netlink notifier might interfer with pending destroy work.
rcu_barrier() is not correct because objects are not release via RCU
callback. Flush destroy work before releasing objects from netlink
notifier path.
Fixes: d4bc8271db21 ("netfilter: nf_tables: netlink notifier might race to release objects")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 5275c4112b57d..539bc5d5c12fd 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -11084,7 +11084,7 @@ static int nft_rcv_nl_event(struct notifier_block *this, unsigned long event,
gc_seq = nft_gc_seq_begin(nft_net);
if (!list_empty(&nf_tables_destroy_list))
- rcu_barrier();
+ nf_tables_trans_destroy_flush_work();
again:
list_for_each_entry(table, &nft_net->tables, list) {
if (nft_table_has_owner(table) &&
