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Date:   Wed, 3 Nov 2021 07:14:27 +0000
From:   Austin Kim <austindh.kim@gmail.com>
To:     mic@digikod.net, serge@hallyn.com
Cc:     serge@hallyn.com, linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, austindh.kim@gmail.com
Subject: [PATCH] landlock: Initialize kernel stack variables properly
Message-ID: <20211103071427.GA13854@raspberrypi>
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In case kernel stack variables are not initialized properly, there might 
be a little chance of kernel information disclosure. So it is better for 
kernel stack variables to be initialized with null characters.

Signed-off-by: Austin Kim <austindh.kim@gmail.com>
---
 security/landlock/syscalls.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c
index 32396962f04d..50a6f7091428 100644
--- a/security/landlock/syscalls.c
+++ b/security/landlock/syscalls.c
@@ -320,6 +320,8 @@ SYSCALL_DEFINE4(landlock_add_rule,
 	if (rule_type != LANDLOCK_RULE_PATH_BENEATH)
 		return -EINVAL;
 
+	memset(&path_beneath_attr, 0, sizeof(path_beneath_attr));
+
 	/* Copies raw user space buffer, only one type for now. */
 	res = copy_from_user(&path_beneath_attr, rule_attr,
 			sizeof(path_beneath_attr));
-- 
2.20.1