From: Matthew Garrett <mjg59@xxxxxxxxxxxxx>
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: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxx>
cc: linux-pm@xxxxxxxxxxxxxxx
Cc: pavel@xxxxxx
Cc: rjw@xxxxxxxxxxxxx
---
kernel/power/user.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 2d8b60a3c86b..99e13fd13237 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", LOCKDOWN_INTEGRITY))
+ return -EPERM;
+
lock_system_sleep();
if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
--
2.21.0.392.gf8f6787159e-goog
