[PATCH 08/24] uswsusp: Disable when the kernel is locked down

[David Howells]

From: Matthew Garrett <mj...@srcf.ucam.org>

uswsusp allows a user process to dump and then restore kernel state, which
makes it possible to modify the running kernel.  Disable this if the kernel
is locked down.

Signed-off-by: Matthew Garrett <mj...@srcf.ucam.org>
Signed-off-by: David Howells <dhowe...@redhat.com>
Reviewed-by: "Lee, Chun-Yi" <j...@suse.com>
Reviewed-by: James Morris <james.l.mor...@oracle.com>
cc: linux...@vger.kernel.org
---

 kernel/power/user.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 75c959de4b29..959b336d8eca 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -52,6 +52,9 @@ static int snapshot_open(struct inode *inode, struct file 
*filp)
        if (!hibernation_available())
                return -EPERM;
 
+       if (kernel_is_locked_down("/dev/snapshot"))
+               return -EPERM;
+
        lock_system_sleep();
 
        if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {