From 5b2fabf7fe8f745ff214ff003e6067b64f172271 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 13 Feb 2025 15:50:20 +0100 Subject: [PATCH] kernfs: Acquire kernfs_rwsem in kernfs_node_dentry(). kernfs_node_dentry() passes kernfs_node::name to lookup_positive_unlocked(). Acquire kernfs_root::kernfs_rwsem to ensure the node is not renamed during the operation. Acked-by: Tejun Heo Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20250213145023.2820193-4-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/mount.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index b9b16e97bff1..4a0ff08d589c 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -209,6 +209,7 @@ struct dentry *kernfs_node_dentry(struct kernfs_node *kn, { struct dentry *dentry; struct kernfs_node *knparent; + struct kernfs_root *root; BUG_ON(sb->s_op != &kernfs_sops); @@ -218,6 +219,9 @@ struct dentry *kernfs_node_dentry(struct kernfs_node *kn, if (!kn->parent) return dentry; + root = kernfs_root(kn); + guard(rwsem_read)(&root->kernfs_rwsem); + knparent = find_next_ancestor(kn, NULL); if (WARN_ON(!knparent)) { dput(dentry); -- 2.50.1