lkml.org 
[lkml]   [2016]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.14 105/130] sparc64: fix incorrect sign extension in sys_sparc64_personality
Date
3.14-stable review patch.  If anyone has any objections, please let me know.

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

From: Dmitry V. Levin <ldv@altlinux.org>

commit 525fd5a94e1be0776fa652df5c687697db508c91 upstream.

The value returned by sys_personality has type "long int".
It is saved to a variable of type "int", which is not a problem
yet because the type of task_struct->pesonality is "unsigned int".
The problem is the sign extension from "int" to "long int"
that happens on return from sys_sparc64_personality.

For example, a userspace call personality((unsigned) -EINVAL) will
result to any subsequent personality call, including absolutely
harmless read-only personality(0xffffffff) call, failing with
errno set to EINVAL.

Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/sparc/kernel/sys_sparc_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -412,7 +412,7 @@ out:

SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality)
{
- int ret;
+ long ret;

if (personality(current->personality) == PER_LINUX32 &&
personality(personality) == PER_LINUX)
\
 
 \ /
  Last update: 2016-03-02 03:21    [W:0.910 / U:0.224 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site