lkml.org 
[lkml]   [2016]   [Nov]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.12 021/127] Fix potential infoleak in older kernels
    Date
    From: Linus Torvalds <torvalds@linux-foundation.org>

    3.12-stable review patch. If anyone has any objections, please let me know.

    ===============

    Not upstream as it is not needed there.

    So a patch something like this might be a safe way to fix the
    potential infoleak in older kernels.

    THIS IS UNTESTED. It's a very obvious patch, though, so if it compiles
    it probably works. It just initializes the output variable with 0 in
    the inline asm description, instead of doing it in the exception
    handler.

    It will generate slightly worse code (a few unnecessary ALU
    operations), but it doesn't have any interactions with the exception
    handler implementation.

    Signed-off-by: Jiri Slaby <jslaby@suse.cz>
    ---
    arch/x86/include/asm/uaccess.h | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
    index 5838fa911aa0..d4d6eb8c08a8 100644
    --- a/arch/x86/include/asm/uaccess.h
    +++ b/arch/x86/include/asm/uaccess.h
    @@ -384,7 +384,7 @@ do { \
    asm volatile("1: mov"itype" %1,%"rtype"0\n" \
    "2:\n" \
    _ASM_EXTABLE_EX(1b, 2b) \
    - : ltype(x) : "m" (__m(addr)))
    + : ltype(x) : "m" (__m(addr)), "0" (0))

    #define __put_user_nocheck(x, ptr, size) \
    ({ \
    --
    2.10.2
    \
     
     \ /
      Last update: 2016-11-25 10:06    [W:9.113 / U:0.648 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site