Patch "zram: fix operator precedence to get offset" has been added to the 4.9-stable tree

Patch "zram: fix operator precedence to get offset" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    zram: fix operator precedence to get offset

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     zram-fix-operator-precedence-to-get-offset.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 4ca82dabc9fbf7bc5322aa54d802cb3cb7b125c5 Mon Sep 17 00:00:00 2001
From: Minchan Kim <minchan@kernel.org>
Date: Thu, 13 Apr 2017 14:56:35 -0700
Subject: zram: fix operator precedence to get offset

From: Minchan Kim <minchan@kernel.org>

commit 4ca82dabc9fbf7bc5322aa54d802cb3cb7b125c5 upstream.

In zram_rw_page, the logic to get offset is wrong by operator precedence
(i.e., "<<" is higher than "&").  With wrong offset, zram can corrupt
the user's data.  This patch fixes it.

Fixes: 8c7f01025 ("zram: implement rw_page operation of zram")
Link: http://lkml.kernel.org/r/1492042622-12074-1-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/block/zram/zram_drv.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -998,7 +998,7 @@ static int zram_rw_page(struct block_dev
 	}
 
 	index = sector >> SECTORS_PER_PAGE_SHIFT;
-	offset = sector & (SECTORS_PER_PAGE - 1) << SECTOR_SHIFT;
+	offset = (sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT;
 
 	bv.bv_page = page;
 	bv.bv_len = PAGE_SIZE;


Patches currently in stable-queue which might be from minchan@kernel.org are

queue-4.9/zram-do-not-use-copy_page-with-non-page-aligned-address.patch
queue-4.9/zram-fix-operator-precedence-to-get-offset.patch
queue-4.9/thp-fix-madv_dontneed-vs.-madv_free-race.patch
queue-4.9/zsmalloc-expand-class-bit.patch

Re: Patch "zram: fix operator precedence to get offset" has been added to the 4.9-stable tree

[Minchan Kim]

On Tue, Apr 18, 2017 at 02:50:42PM +0200, gregkh@linuxfoundation.org wrote:
> 
> This is a note to let you know that I've just added the patch titled
> 
>     zram: fix operator precedence to get offset
> 
> to the 4.9-stable tree which can be found at:
>     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> 
> The filename of the patch is:
>      zram-fix-operator-precedence-to-get-offset.patch
> and it can be found in the queue-4.9 subdirectory.
> 
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable@vger.kernel.org> know about it.
> 
> 
> From 4ca82dabc9fbf7bc5322aa54d802cb3cb7b125c5 Mon Sep 17 00:00:00 2001
> From: Minchan Kim <minchan@kernel.org>
> Date: Thu, 13 Apr 2017 14:56:35 -0700
> Subject: zram: fix operator precedence to get offset
> 
> From: Minchan Kim <minchan@kernel.org>
> 
> commit 4ca82dabc9fbf7bc5322aa54d802cb3cb7b125c5 upstream.
> 
> In zram_rw_page, the logic to get offset is wrong by operator precedence
> (i.e., "<<" is higher than "&").  With wrong offset, zram can corrupt
> the user's data.  This patch fixes it.
> 
> Fixes: 8c7f01025 ("zram: implement rw_page operation of zram")
> Link: http://lkml.kernel.org/r/1492042622-12074-1-git-send-email-minchan@kernel.org
> Signed-off-by: Minchan Kim <minchan@kernel.org>
> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

After Linus merging this patch, I got realized that patch itself is correct
but no need to apply this patch to the stable by review from Sergey.

Please drop this patch.
Sorry for the noise caused by zram.