From: Sebastian Andrzej Siewior Date: Thu, 13 Feb 2025 14:50:19 +0000 (+0100) Subject: kernfs: Acquire kernfs_rwsem in kernfs_get_parent_dentry(). X-Git-Tag: v6.15-rc1~79^2~52 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=122ab92dee80582c39740609a627198dd5b6b595;p=thirdparty%2Fkernel%2Flinux.git 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 Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20250213145023.2820193-3-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 1358c21837f1a..b9b16e97bff18 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -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)); }