linux-kernel - [PATCH 3.2 147/199] futex: Move futex_init() to core

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: <lsq.1489146370.566511801@decadent.org.uk>
Date:   Fri, 10 Mar 2017 11:46:10 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "Thomas Gleixner" <tglx@...utronix.de>,
        zhong.weidong@....com.cn, deng.huali@....com.cn,
        "Yang Yang" <yang.yang29@....com.cn>, jiang.zhengxiong@....com.cn,
        jiang.biao2@....com.cn, "Peter Zijlstra" <peterz@...radead.org>
Subject: [PATCH 3.2 147/199] futex: Move futex_init() to core_initcall

3.2.87-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Yang Yang <yang.yang29@....com.cn>

commit 25f71d1c3e98ef0e52371746220d66458eac75bc upstream.

The UEVENT user mode helper is enabled before the initcalls are executed
and is available when the root filesystem has been mounted.

The user mode helper is triggered by device init calls and the executable
might use the futex syscall.

futex_init() is marked __initcall which maps to device_initcall, but there
is no guarantee that futex_init() is invoked _before_ the first device init
call which triggers the UEVENT user mode helper.

If the user mode helper uses the futex syscall before futex_init() then the
syscall crashes with a NULL pointer dereference because the futex subsystem
has not been initialized yet.

Move futex_init() to core_initcall so futexes are initialized before the
root filesystem is mounted and the usermode helper becomes available.

[ tglx: Rewrote changelog ]

Signed-off-by: Yang Yang <yang.yang29@....com.cn>
Cc: jiang.biao2@....com.cn
Cc: jiang.zhengxiong@....com.cn
Cc: zhong.weidong@....com.cn
Cc: deng.huali@....com.cn
Cc: Peter Zijlstra <peterz@...radead.org>
Link: http://lkml.kernel.org/r/1483085875-6130-1-git-send-email-yang.yang29@zte.com.cn
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 kernel/futex.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2904,4 +2904,4 @@ static int __init futex_init(void)

 	return 0;
 }
-__initcall(futex_init);
+core_initcall(futex_init);