[PATCH] selinux: fix missing dput() before selinuxfs unmount

2018-04-09 Thread Stephen Smalley
Commit 0619f0f5e36f ("selinux: wrap selinuxfs state") triggers
a BUG when SELinux is runtime-disabled (i.e. systemd or equivalent
disables SELinux before initial policy load via /sys/fs/selinux/disable
based on /etc/selinux/config SELINUX=disabled).  This does not manifest
if SELinux is disabled via kernel command line argument or if
SELinux is enabled (permissive or enforcing).

Before:
SELinux:  Disabled at runtime.
BUG: Dentry 6d77e5c7{i=17,n=null}  still in use (1) [unmount of 
selinuxfs selinuxfs]

After:
SELinux:  Disabled at runtime.

Fixes: 0619f0f5e36f ("selinux: wrap selinuxfs state")
Reported-by: Tetsuo Handa 
Reported-by: Dmitry Vyukov 
Signed-off-by: Stephen Smalley 
---
 security/selinux/selinuxfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 4be683eeba01..245160373dab 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -2061,6 +2061,7 @@ __initcall(init_sel_fs);
 void exit_sel_fs(void)
 {
sysfs_remove_mount_point(fs_kobj, "selinux");
+   dput(selinux_null.dentry);
kern_unmount(selinuxfs_mount);
unregister_filesystem(&sel_fs_type);
 }
-- 
2.14.3



Re: [PATCH] selinux: fix missing dput() before selinuxfs unmount

2018-04-09 Thread Linus Torvalds
On Mon, Apr 9, 2018 at 11:36 AM, Stephen Smalley  wrote:
> Commit 0619f0f5e36f ("selinux: wrap selinuxfs state") triggers
> a BUG when SELinux is runtime-disabled (i.e. systemd or equivalent
> disables SELinux before initial policy load via /sys/fs/selinux/disable
> based on /etc/selinux/config SELINUX=disabled).

Thanks, applied.

   Linus