From f67b4da1dfb1d0986b998e2260766cff2b29b38f Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Wed, 8 Nov 2017 15:11:33 +0000 Subject: [PATCH] uswsusp: Disable when the kernel is locked down 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 Signed-off-by: David Howells Reviewed-by: "Lee, Chun-Yi" Reviewed-by: James Morris cc: linux-pm@vger.kernel.org Gbp-Pq: Topic features/all/lockdown Gbp-Pq: Name 0010-uswsusp-Disable-when-the-kernel-is-locked-down.patch --- kernel/power/user.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/power/user.c b/kernel/power/user.c index 22df9f7ff67..678ade9decf 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)) { -- 2.30.2