Patch "zram: fix operator precedence to get offset" has been added to the 4.10-stable tree

Patch "zram: fix operator precedence to get offset" has been added to the 4.10-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 4.10-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-4.10 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
@@ -999,7 +999,7 @@ 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-4.10/zram-do-not-use-copy_page-with-non-page-aligned-address.patch
queue-4.10/zram-fix-operator-precedence-to-get-offset.patch
queue-4.10/thp-fix-madv_dontneed-vs.-madv_free-race.patch
queue-4.10/zsmalloc-expand-class-bit.patch

Re: Patch "zram: fix operator precedence to get offset" has been added to the 4.10-stable tree

[Minchan Kim]

Hi Greg,

On Tue, Apr 18, 2017 at 02:49:13PM +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 4.10-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-4.10 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.
Sorry about the noise.

Please drop this patch.

Re: Patch "zram: fix operator precedence to get offset" has been added to the 4.10-stable tree

[Greg KH]

On Wed, Apr 19, 2017 at 09:56:56AM +0900, Minchan Kim wrote:
> Hi Greg,
> 
> On Tue, Apr 18, 2017 at 02:49:13PM +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 4.10-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-4.10 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.
> Sorry about the noise.
> 
> Please drop this patch.

Not a problem, now dropped from all 3 trees, thanks for letting me know.

greg k-h