On Mar 28, 2024 =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgoettsche@xxxxxxxxxxxxx> wrote:
>
> In case kern_mount() fails and returns an error pointer return in the
> error branch instead of continuing and dereferencing the error pointer.
>
> While on it drop the never read static variable selinuxfs_mount.
>
> Fixes: 0619f0f5e36f ("selinux: wrap selinuxfs state")
> Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
> ---
> security/selinux/selinuxfs.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
> index d18581d741e8..7e9aa5d151b4 100644
> --- a/security/selinux/selinuxfs.c
> +++ b/security/selinux/selinuxfs.c
> @@ -2125,7 +2125,6 @@ static struct file_system_type sel_fs_type = {
> .kill_sb = sel_kill_sb,
> };
>
> -static struct vfsmount *selinuxfs_mount __ro_after_init;
> struct path selinux_null __ro_after_init;
>
> static int __init init_sel_fs(void)
> @@ -2147,18 +2146,21 @@ static int __init init_sel_fs(void)
> return err;
> }
>
> - selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
> - if (IS_ERR(selinuxfs_mount)) {
> + selinux_null.mnt = kern_mount(&sel_fs_type);
> + if (IS_ERR(selinux_null.mnt)) {
> pr_err("selinuxfs: could not mount!\n");
> - err = PTR_ERR(selinuxfs_mount);
> - selinuxfs_mount = NULL;
> + err = PTR_ERR(selinux_null.mnt);
> + selinux_null.mnt = NULL;
> + return err;
> }
> +
> selinux_null.dentry = d_hash_and_lookup(selinux_null.mnt->mnt_root,
> &null_name);
> if (IS_ERR(selinux_null.dentry)) {
> pr_err("selinuxfs: could not lookup null!\n");
> err = PTR_ERR(selinux_null.dentry);
> selinux_null.dentry = NULL;
> + return err;
Casey's correct in that we probably don't need this, but it does harden
the source a bit against future changes so it isn't entirely a bad
thing. If nothing else, some new kernel dev will get excited writing a
oneliner several years from now that removes the redundant return; I'm
getting exited about the patch just thinking about it.
Anyway, thanks for noticing this and submitting a patch Christian,
beyond the above nitpick, everything looks good to me. I'm going to
merge this into selinux/stable-6.9 with a stable marking and assuming
all goes well I'll send this up to Linus in a few days.
Thanks!
> }
>
> return err;
> --
> 2.43.0
--
paul-moore.com
