Messages in this thread Patch in this message | | | From | Liu Xiaodong <> | Subject | [PATCH] block: ublk: extending queue_size to fix overflow | Date | Tue, 31 Jan 2023 02:05:52 -0500 |
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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 <xiaodong.liu@intel.com> --- 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 e54693204630..6368b56eacf1 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; -- 2.14.5
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