[08/24] uswsusp: Disable when the kernel is locked down

Commit Message

David Howells April 11, 2018, 4:25 p.m. UTC

From: Matthew Garrett <[e-mail]>

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 <[e-mail]>
Signed-off-by: David Howells <[e-mail]>
Reviewed-by: "Lee, Chun-Yi" <[e-mail]>
Reviewed-by: James Morris <[e-mail]>
cc: [e-mail]
---

 kernel/power/user.c |    3 +++
 1 file changed, 3 insertions(+)


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Patch

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 75c959de4b29..959b336d8eca 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)) {