From: Matthew Garrett <[email protected]> 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 <[email protected]> Signed-off-by: David Howells <[email protected]> Reviewed-by: "Lee, Chun-Yi" <[email protected]> Reviewed-by: James Morris <[email protected]> cc: [email protected] --- kernel/power/user.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/power/user.c b/kernel/power/user.c index 22df9f7ff672..678ade9decfe 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)) {
