From: Jordan Niethe <jniethe5@gmail.com>
Date: Wed, 27 Feb 2019 03:02:29 +0000 (+1100)
Subject: powerpc/powernv: Make opal log only readable by root
X-Git-Tag: v4.9.165~24
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f3b4d46f73bf9c32acdde0ac53fd98df9ff3aa90;p=thirdparty%2Fkernel%2Fstable.git

powerpc/powernv: Make opal log only readable by root

commit 7b62f9bd2246b7d3d086e571397c14ba52645ef1 upstream.

Currently the opal log is globally readable. It is kernel policy to
limit the visibility of physical addresses / kernel pointers to root.
Given this and the fact the opal log may contain this information it
would be better to limit the readability to root.

Fixes: bfc36894a48b ("powerpc/powernv: Add OPAL message log interface")
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Stewart Smith <stewart@linux.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/powerpc/platforms/powernv/opal-msglog.c b/arch/powerpc/platforms/powernv/opal-msglog.c
index 39d6ff9e56309..d10bad14097bc 100644
--- a/arch/powerpc/platforms/powernv/opal-msglog.c
+++ b/arch/powerpc/platforms/powernv/opal-msglog.c
@@ -98,7 +98,7 @@ static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
 }
 
 static struct bin_attribute opal_msglog_attr = {
-	.attr = {.name = "msglog", .mode = 0444},
+	.attr = {.name = "msglog", .mode = 0400},
 	.read = opal_msglog_read
 };