Some subsystems want to add debugfs files at early boot, way before debugfs is initialized. This seems to work somehow as the vfs layer will not allow it to happen, but let's be explicit and test to ensure we are properly up and running before allowing files to be created. Reported-by: Michael Walle <michael@xxxxxxxx> Reported-by: Marc Zyngier <maz@xxxxxxxxxx> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/debugfs/inode.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index bbeb563cbe78..86c7f0489620 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -318,6 +318,9 @@ static struct dentry *start_creating(const char *name, struct dentry *parent) if (!(debugfs_allow & DEBUGFS_ALLOW_API)) return ERR_PTR(-EPERM); + if (!debugfs_initialized()) + return ERR_PTR(-ENOENT); + pr_debug("creating file '%s'\n", name); if (IS_ERR(parent)) -- 2.30.1