Commit 5b2fabf7 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Greg Kroah-Hartman
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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: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20250213145023.2820193-4-bigeasy@linutronix.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 122ab92d

fs/kernfs/mount.c

+4 −0
Original line number Diff line number Diff line
@@ -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);