From: David Howells <dhowells@redhat.com> stable inclusion from stable-v5.10.135 commit 45a84f04a9a08a43a4ef7f6d5a965fbf664c802f category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5ZWFM Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- 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 <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> --- 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 e5d22af43fa0..f78f90910398 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); -- 2.20.1