From: Matthew Garrett Date: Wed, 5 Apr 2017 17:40:30 +0100 Subject: [48/61] uswsusp: Disable when the kernel is locked down Origin: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit?id=6c773b2f00bec7cdccc1adf4a1af1afb082b78b8 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 --- kernel/power/user.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/power/user.c b/kernel/power/user.c index 22df9f7ff672..e4b926d329b7 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()) + return -EPERM; + lock_system_sleep(); if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {