4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Johannes Thumshirn <[email protected]> [ 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 <[email protected]> Reviewed-by: Hannes Reinecke <[email protected]> Reviewed-by: Sergey Senozhatsky <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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
