From 400188ae361a9d9a72a47a6cedaf2d2efcc84aa8 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 13 Feb 2025 15:50:18 +0100 Subject: [PATCH] kernfs: Acquire kernfs_rwsem in kernfs_notify_workfn(). kernfs_notify_workfn() dereferences kernfs_node::name and passes it later to fsnotify(). If the node is renamed then the previously observed name pointer becomes invalid. Acquire kernfs_root::kernfs_rwsem to block renames of the node. Acked-by: Tejun Heo Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20250213145023.2820193-2-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/file.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 0eb320617d7b..c4ffa8dc89eb 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -911,6 +911,7 @@ repeat: /* kick fsnotify */ down_read(&root->kernfs_supers_rwsem); + down_read(&root->kernfs_rwsem); list_for_each_entry(info, &kernfs_root(kn)->supers, node) { struct kernfs_node *parent; struct inode *p_inode = NULL; @@ -947,6 +948,7 @@ repeat: iput(inode); } + up_read(&root->kernfs_rwsem); up_read(&root->kernfs_supers_rwsem); kernfs_put(kn); goto repeat; -- 2.50.1