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@xxxxxxxxxxxxxxx> know about it.
>From 4ca82dabc9fbf7bc5322aa54d802cb3cb7b125c5 Mon Sep 17 00:00:00 2001
From: Minchan Kim <minchan@xxxxxxxxxx>
Date: Thu, 13 Apr 2017 14:56:35 -0700
Subject: zram: fix operator precedence to get offset
From: Minchan Kim <minchan@xxxxxxxxxx>
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@xxxxxxxxxx
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxx 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