Commit 122ab92d authored Feb 13, 2025 by Sebastian Andrzej Siewior Committed by Greg Kroah-Hartman Feb 15, 2025

kernfs: Acquire kernfs_rwsem in kernfs_get_parent_dentry().



kernfs_get_parent_dentry() passes kernfs_node::parent to
kernfs_get_inode().

Acquire kernfs_root::kernfs_rwsem to ensure kernfs_node::parent isn't
replaced during the operation.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20250213145023.2820193-3-bigeasy@linutronix.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 400188ae

fs/kernfs/mount.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -145,7 +145,9 @@ static struct dentry kernfs_fh_to_parent(struct super_block sb,
		static struct dentry kernfs_get_parent_dentry(struct dentry child)
		{
		struct kernfs_node *kn = kernfs_dentry_node(child);
		struct kernfs_root *root = kernfs_root(kn);

		guard(rwsem_read)(&root->kernfs_rwsem);
		return d_obtain_alias(kernfs_get_inode(child->d_sb, kn->parent));
		}