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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <152346393165.4030.14932574511330889453.stgit@warthog.procyon.org.uk>
Date:   Wed, 11 Apr 2018 17:25:31 +0100
From:   David Howells <dhowells@...hat.com>
To:     torvalds@...ux-foundation.org
Cc:     linux-man@...r.kernel.org, linux-api@...r.kernel.org,
        jmorris@...ei.org, linux-kernel@...r.kernel.org,
        dhowells@...hat.com, linux-security-module@...r.kernel.org
Subject: [PATCH 08/24] uswsusp: Disable when the kernel is locked down

From: Matthew Garrett <mjg59@...f.ucam.org>

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 <mjg59@...f.ucam.org>
Signed-off-by: David Howells <dhowells@...hat.com>
Reviewed-by: "Lee, Chun-Yi" <jlee@...e.com>
Reviewed-by: James Morris <james.l.morris@...cle.com>
cc: linux-pm@...r.kernel.org
---

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

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)) {