From: Sebastian Andrzej Siewior bigeasy@linutronix.de
[ Upstream commit 122ab92dee80582c39740609a627198dd5b6b595 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- fs/kernfs/mount.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index c4bf26142eec9..5fda25dbbd256 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -147,7 +147,9 @@ 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)); }