On Thu, Apr 11, 2019 at 03:34:43AM +1000, James Morris wrote:
> On Fri, 15 Mar 2019, Kangjie Lu wrote:
>
> > securityfs_create_file may fail. The fix checks its status and
> > returns the error code upstream if it fails.
> >
> > Signed-off-by: Kangjie Lu <k...@umn.edu>
> >
>
> Applied to
> git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git
> next-general
>
> > ---
> > Return the exact error code upstream.
> > ---
> > security/inode.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/security/inode.c b/security/inode.c
> > index b7772a9b315e..667f8b15027d 100644
> > --- a/security/inode.c
> > +++ b/security/inode.c
> > @@ -339,6 +339,11 @@ static int __init securityfs_init(void)
> > #ifdef CONFIG_SECURITY
> > lsm_dentry = securityfs_create_file("lsm", 0444, NULL, NULL,
> > &lsm_ops);
> > + if (IS_ERR(lsm_dentry)) {
> > + unregister_filesystem(&fs_type);
> > + sysfs_remove_mount_point(kernel_kobj, "security");
> > + return PTR_ERR(lsm_dentry);
> > + }
Rather bad way to do it - generally, register_filesystem() should be
the last thing done by initialization. Any modular code that
does unregister_filesystem() on failure exit is flat-out broken;
here it's not instantly FUBAR, but it's a bloody bad example.
What's more, why not let simple_fill_super() do it? Just
static int fill_super(struct super_block *sb, void *data, int silent)
{
static const struct tree_descr files[] = {
#ifdef CONFIG_SECURITY
{"lsm", &lsm_ops, 0444},
#endif
{""}
};
and to hell with that call of securityfs_create_file() and all its
failure handling...
