This is a note to let you know that I've just added the patch titled
netfilter: nft_set_rbtree: use read spinlock to avoid datapath contention
to the 5.4-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-nft_set_rbtree-use-read-spinlock-to-avoid-datapath-contention.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable-owner@xxxxxxxxxxxxxxx Tue Nov 21 12:13:57 2023
From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Date: Tue, 21 Nov 2023 13:13:25 +0100
Subject: netfilter: nft_set_rbtree: use read spinlock to avoid datapath contention
To: netfilter-devel@xxxxxxxxxxxxxxx
Cc: gregkh@xxxxxxxxxxxxxxxxxxx, sashal@xxxxxxxxxx, stable@xxxxxxxxxxxxxxx
Message-ID: <20231121121333.294238-19-pablo@xxxxxxxxxxxxx>
From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
commit 96b33300fba880ec0eafcf3d82486f3463b4b6da upstream.
rbtree GC does not modify the datastructure, instead it collects expired
elements and it enqueues a GC transaction. Use a read spinlock instead
to avoid data contention while GC worker is running.
Fixes: f6c383b8c31a ("netfilter: nf_tables: adapt set backend to use GC transaction API")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/netfilter/nft_set_rbtree.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -626,8 +626,7 @@ static void nft_rbtree_gc(struct work_st
if (!gc)
goto done;
- write_lock_bh(&priv->lock);
- write_seqcount_begin(&priv->count);
+ read_lock_bh(&priv->lock);
for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
/* Ruleset has been updated, try later. */
@@ -676,8 +675,7 @@ dead_elem:
}
try_later:
- write_seqcount_end(&priv->count);
- write_unlock_bh(&priv->lock);
+ read_unlock_bh(&priv->lock);
if (gc)
nft_trans_gc_queue_async_done(gc);
Patches currently in stable-queue which might be from stable-owner@xxxxxxxxxxxxxxx are
queue-5.4/netfilter-nf_tables-fix-memleak-when-more-than-255-elements-expired.patch
queue-5.4/netfilter-nft_set_rbtree-fix-overlap-expiration-walk.patch
queue-5.4/netfilter-nf_tables-use-correct-lock-to-protect-gc_list.patch
queue-5.4/netfilter-nf_tables-disable-toggling-dormant-table-state-more-than-once.patch
queue-5.4/netfilter-nf_tables-gc-transaction-race-with-netns-dismantle.patch
queue-5.4/netfilter-nf_tables-drop-map-element-references-from-preparation-phase.patch
queue-5.4/netfilter-nf_tables-fix-gc-transaction-races-with-netns-and-netlink-event-exit-path.patch
queue-5.4/netfilter-nf_tables-don-t-skip-expired-elements-during-walk.patch
queue-5.4/netfilter-nf_tables-remove-busy-mark-and-gc-batch-api.patch
queue-5.4/netfilter-nf_tables-gc-transaction-race-with-abort-path.patch
queue-5.4/netfilter-nf_tables-unregister-flowtable-hooks-on-netns-exit.patch
queue-5.4/netfilter-nft_set_rbtree-switch-to-node-list-walk-for-overlap-detection.patch
queue-5.4/netfilter-nf_tables-adapt-set-backend-to-use-gc-transaction-api.patch
queue-5.4/netfilter-nftables-rename-set-element-data-activation-deactivation-functions.patch
queue-5.4/netfilter-nft_set_rbtree-skip-sync-gc-for-new-elements-in-this-transaction.patch
queue-5.4/netfilter-nf_tables-pass-context-to-nft_set_destroy.patch
queue-5.4/netfilter-nf_tables-bogus-ebusy-when-deleting-flowtable-after-flush-for-5.4.patch
queue-5.4/netfilter-nft_set_hash-try-later-when-gc-hits-eagain-on-iteration.patch
queue-5.4/netfilter-nf_tables-defer-gc-run-if-previous-batch-is-still-pending.patch
queue-5.4/netfilter-nft_set_rbtree-use-read-spinlock-to-avoid-datapath-contention.patch
queue-5.4/netfilter-nf_tables-double-hook-unregistration-in-netns-path.patch
queue-5.4/netfilter-nftables-update-table-flags-from-the-commit-phase.patch
queue-5.4/netfilter-nft_set_hash-mark-set-element-as-dead-when-deleting-from-packet-path.patch
queue-5.4/netfilter-nf_tables-gc-transaction-api-to-avoid-race-with-control-plane.patch
queue-5.4/netfilter-nf_tables-fix-table-flag-updates.patch
queue-5.4/netfilter-nft_set_rbtree-fix-null-deref-on-element-insertion.patch
