From 093610f216d0722d375af048fb1c0e565003407f Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 28 Jul 2022 10:31:06 +0100 Subject: [PATCH] watch_queue: Fix missing rcu annotation commit e0339f036ef4beb9b20f0b6532a1e0ece7f594c6 upstream. Since __post_watch_notification() walks wlist->watchers with only the RCU read lock held, we need to use RCU methods to add to the list (we already use RCU methods to remove from the list). Fix add_watch_to_object() to use hlist_add_head_rcu() instead of hlist_add_head() for that list. Fixes: c73be61cede5 ("pipe: Add general notification queue support") Signed-off-by: David Howells Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/watch_queue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c index debebcd2664e..7019d337ce86 100644 --- a/kernel/watch_queue.c +++ b/kernel/watch_queue.c @@ -497,7 +497,7 @@ int add_watch_to_object(struct watch *watch, struct watch_list *wlist) unlock_wqueue(wqueue); } - hlist_add_head(&watch->list_node, &wlist->watchers); + hlist_add_head_rcu(&watch->list_node, &wlist->watchers); return 0; } EXPORT_SYMBOL(add_watch_to_object);