linux-kernel - [tip:core/urgent] linux/kernel.h: Use parentheses around argument in u64_to_user

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]

Date:   Wed, 3 Apr 2019 04:10:12 -0700
From:   tip-bot for Jann Horn <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, gregkh@...uxfoundation.org,
        keescook@...omium.org, jannh@...gle.com, bp@...e.de,
        tglx@...utronix.de, hpa@...or.com, x86@...nel.org,
        avagin@...nvz.org, akpm@...ux-foundation.org,
        dan.carpenter@...cle.com, mojha@...eaurora.org, neilb@...e.com,
        yamada.masahiro@...ionext.com, peterz@...radead.org,
        qiaowei.ren@...el.com, mingo@...nel.org, jani.nikula@...el.com
Subject: [tip:core/urgent] linux/kernel.h: Use parentheses around argument
 in u64_to_user_ptr()

Commit-ID:  a0fe2c6479aab5723239b315ef1b552673f434a3
Gitweb:     https://git.kernel.org/tip/a0fe2c6479aab5723239b315ef1b552673f434a3
Author:     Jann Horn <jannh@...gle.com>
AuthorDate: Fri, 29 Mar 2019 22:46:49 +0100
Committer:  Borislav Petkov <bp@...e.de>
CommitDate: Wed, 3 Apr 2019 11:43:49 +0200

linux/kernel.h: Use parentheses around argument in u64_to_user_ptr()

Use parentheses around uses of the argument in u64_to_user_ptr() to
ensure that the cast doesn't apply to part of the argument.

There are existing uses of the macro of the form

  u64_to_user_ptr(A + B)

which expands to

  (void __user *)(uintptr_t)A + B

(the cast applies to the first operand of the addition, the addition
is a pointer addition). This happens to still work as intended, the
semantic difference doesn't cause a difference in behavior.

But I want to use u64_to_user_ptr() with a ternary operator in the
argument, like so:

  u64_to_user_ptr(A ? B : C)

This currently doesn't work as intended.

Signed-off-by: Jann Horn <jannh@...gle.com>
Signed-off-by: Borislav Petkov <bp@...e.de>
Reviewed-by: Mukesh Ojha <mojha@...eaurora.org>
Cc: Andrei Vagin <avagin@...nvz.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Dan Carpenter <dan.carpenter@...cle.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: "H. Peter Anvin" <hpa@...or.com>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Jani Nikula <jani.nikula@...el.com>
Cc: Kees Cook <keescook@...omium.org>
Cc: Masahiro Yamada <yamada.masahiro@...ionext.com>
Cc: NeilBrown <neilb@...e.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Qiaowei Ren <qiaowei.ren@...el.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: x86-ml <x86@...nel.org>
Link: https://lkml.kernel.org/r/20190329214652.258477-1-jannh@google.com
---
 include/linux/kernel.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 34a5036debd3..2d14e21c16c0 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -47,8 +47,8 @@
 
 #define u64_to_user_ptr(x) (		\
 {					\
-	typecheck(u64, x);		\
-	(void __user *)(uintptr_t)x;	\
+	typecheck(u64, (x));		\
+	(void __user *)(uintptr_t)(x);	\
 }					\
 )