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
Signed-off-by: Matthew Garrett <matthewgarr...@google.com>
---
kernel/power/user.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 2d8b60a3c86b..0305d513c274 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)) {
--
2.21.0.352.gf09ad66450-goog
