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%3Ba=su...

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