Patch "zram: set physical queue limits to avoid array out of bounds accesses" has been added to the 4.4-stable tree

Patch "zram: set physical queue limits to avoid array out of bounds accesses" has been added to the 4.4-stable tree

[gregkh]

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

    zram: set physical queue limits to avoid array out of bounds accesses

to the 4.4-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-set-physical-queue-limits-to-avoid-array-out-of-bounds-accesses.patch
and it can be found in the queue-4.4 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 foo@baz Tue Dec 12 13:38:50 CET 2017
From: Johannes Thumshirn <jthumshirn@suse.de>
Date: Mon, 6 Mar 2017 11:23:35 +0100
Subject: zram: set physical queue limits to avoid array out of bounds accesses

From: Johannes Thumshirn <jthumshirn@suse.de>


[ Upstream commit 0bc315381fe9ed9fb91db8b0e82171b645ac008f ]

zram can handle at most SECTORS_PER_PAGE sectors in a bio's bvec. When using
the NVMe over Fabrics loopback target which potentially sends a huge bulk of
pages attached to the bio's bvec this results in a kernel panic because of
array out of bounds accesses in zram_decompress_page().

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/block/zram/zram_drv.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1247,6 +1247,8 @@ static int zram_add(void)
 	blk_queue_io_min(zram->disk->queue, PAGE_SIZE);
 	blk_queue_io_opt(zram->disk->queue, PAGE_SIZE);
 	zram->disk->queue->limits.discard_granularity = PAGE_SIZE;
+	zram->disk->queue->limits.max_sectors = SECTORS_PER_PAGE;
+	zram->disk->queue->limits.chunk_sectors = 0;
 	blk_queue_max_discard_sectors(zram->disk->queue, UINT_MAX);
 	/*
 	 * zram_bio_discard() will clear all logical blocks if logical block


Patches currently in stable-queue which might be from jthumshirn@suse.de are

queue-4.4/zram-set-physical-queue-limits-to-avoid-array-out-of-bounds-accesses.patch