linux-kernel - [PATCH AUTOSEL 4.4 02/38] tomoyo: fix clang pointer arithmetic warning

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <20201223022516.2794471-2-sashal@kernel.org>
Date:   Tue, 22 Dec 2020 21:24:40 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Arnd Bergmann <arnd@...db.de>,
        Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>,
        Sasha Levin <sashal@...nel.org>,
        linux-security-module@...r.kernel.org,
        clang-built-linux@...glegroups.com
Subject: [PATCH AUTOSEL 4.4 02/38] tomoyo: fix clang pointer arithmetic warning

From: Arnd Bergmann <arnd@...db.de>

[ Upstream commit d9594e0409651a237903a13c9718df889f43d43b ]

clang warns about additions on NULL pointers being undefined in C:

security/tomoyo/securityfs_if.c:226:59: warning: arithmetic on a null pointer treated as a cast from integer to pointer is a GNU extension [-Wnull-pointer-arithmetic]
        securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,

Change the code to instead use a cast through uintptr_t to avoid
the warning.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
Signed-off-by: Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 security/tomoyo/securityfs_if.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/security/tomoyo/securityfs_if.c b/security/tomoyo/securityfs_if.c
index 179a955b319df..1e6a4ed5ae54d 100644
--- a/security/tomoyo/securityfs_if.c
+++ b/security/tomoyo/securityfs_if.c
@@ -135,8 +135,8 @@ static const struct file_operations tomoyo_self_operations = {
  */
 static int tomoyo_open(struct inode *inode, struct file *file)
 {
-	const int key = ((u8 *) file_inode(file)->i_private)
-		- ((u8 *) NULL);
+	const u8 key = (uintptr_t) file_inode(file)->i_private;
+
 	return tomoyo_open_control(key, file);
 }
 
@@ -227,7 +227,7 @@ static const struct file_operations tomoyo_operations = {
 static void __init tomoyo_create_entry(const char *name, const umode_t mode,
 				       struct dentry *parent, const u8 key)
 {
-	securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
+	securityfs_create_file(name, mode, parent, (void *) (uintptr_t) key,
 			       &tomoyo_operations);
 }
 
-- 
2.27.0