From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: [PATCH 09/12] uswsusp: Disable when securelevel is set Date: Mon, 9 Sep 2013 11:49:43 -0400 Message-ID: <1378741786-18430-10-git-send-email-matthew.garrett@nebula.com> References: <1378741786-18430-1-git-send-email-matthew.garrett@nebula.com> Return-path: In-Reply-To: <1378741786-18430-1-git-send-email-matthew.garrett@nebula.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: keescook@chromium.org, gregkh@linuxfoundation.org, hpa@zytor.com, linux-efi@vger.kernel.org, jmorris@namei.org, linux-security-module@vger.kernel.org, Matthew Garrett List-Id: linux-efi@vger.kernel.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 securelevel has been set. Signed-off-by: Matthew Garrett --- kernel/power/user.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/power/user.c b/kernel/power/user.c index 4ed81e7..520a9c4 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -24,6 +24,7 @@ #include #include #include +#include #include @@ -48,6 +49,9 @@ static int snapshot_open(struct inode *inode, struct file *filp) struct snapshot_data *data; int error; + if (get_securelevel() > 0) + return -EPERM; + lock_system_sleep(); if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { -- 1.8.3.1