diff mbox series

[net,2/6] netfilter: nf_tables: flush pending destroy work before netlink notifier

Message ID 20230823152711.15279-3-fw@strlen.de (mailing list archive)
State Accepted
Commit 2c9f0293280e258606e54ed2b96fa71498432eae
Delegated to: Netdev Maintainers
Headers show
Series [net,1/6] netfilter: nf_tables: validate all pending tables | expand

Checks

Context Check Description
netdev/series_format success Pull request is its own cover letter
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1344 this patch: 1344
netdev/cc_maintainers warning 2 maintainers not CCed: coreteam@netfilter.org kadlec@netfilter.org
netdev/build_clang success Errors and warnings before: 1351 this patch: 1351
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1367 this patch: 1367
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Florian Westphal Aug. 23, 2023, 3:26 p.m. UTC 
From: Pablo Neira Ayuso <pablo@netfilter.org>

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@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 net/netfilter/nf_tables_api.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index a76a62ebe9c9..d299e7aa1b96 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -11073,7 +11073,7 @@  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) &&