From 29baef789c838bd5c02f50c88adbbc6b955aaf61 Mon Sep 17 00:00:00 2001 From: Liu Xiaodong Date: Tue, 31 Jan 2023 02:05:52 -0500 Subject: [PATCH] block: ublk: extending queue_size to fix overflow When validating drafted SPDK ublk target, in a case that assigning large queue depth to multiqueue ublk device, ublk target would run into a weird incorrect state. During rounds of review and debug, An overflow bug was found in ublk driver. In ublk_cmd.h, UBLK_MAX_QUEUE_DEPTH is 4096 which means each ublk queue depth can be set as large as 4096. But when setting qd for a ublk device, sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io) will be larger than 65535 if qd is larger than 2728. Then queue_size is overflowed, and ublk_get_queue() references a wrong pointer position. The wrong content of ublk_queue elements will lead to out-of-bounds memory access. Extend queue_size in ublk_device as "unsigned int". Signed-off-by: Liu Xiaodong Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver") Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20230131070552.115067-1-xiaodong.liu@intel.com Signed-off-by: Jens Axboe --- drivers/block/ublk_drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index e546932..6368b56e 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -137,7 +137,7 @@ struct ublk_device { char *__queues; - unsigned short queue_size; + unsigned int queue_size; struct ublksrv_ctrl_dev_info dev_info; struct blk_mq_tag_set tag_set; -- 2.7.4