| Message ID | b70eb4a71a01a72a75f2f1efb1fadc4ef77fc7ff.1503693884.git.shli@fb.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 08/25/2017 02:46 PM, Shaohua Li wrote: > Dan reported this: > > The patch 2984c8684f96: "nullb: factor disk parameters" from Aug 14, > 2017, leads to the following Smatch complaint: > > drivers/block/null_blk.c:1759 null_init_tag_set() > error: we previously assumed 'nullb' could be null (see line > 1750) > > 1755 set->cmd_size = sizeof(struct nullb_cmd); > 1756 set->flags = BLK_MQ_F_SHOULD_MERGE; > 1757 set->driver_data = NULL; > 1758 > 1759 if (nullb->dev->blocking) > ^^^^^^^^^^^^^^^^^^^^ > And an unchecked dereference. > > nullb could be NULL here. Applied, thanks. Fixed up your subject line typo.
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index 2032360..4d328e3 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -1756,7 +1756,7 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set) set->flags = BLK_MQ_F_SHOULD_MERGE; set->driver_data = NULL; - if (nullb->dev->blocking) + if ((nullb && nullb->dev->blocking) || g_blocking) set->flags |= BLK_MQ_F_BLOCKING; return blk_mq_alloc_tag_set(set);
Dan reported this: The patch 2984c8684f96: "nullb: factor disk parameters" from Aug 14, 2017, leads to the following Smatch complaint: drivers/block/null_blk.c:1759 null_init_tag_set() error: we previously assumed 'nullb' could be null (see line 1750) 1755 set->cmd_size = sizeof(struct nullb_cmd); 1756 set->flags = BLK_MQ_F_SHOULD_MERGE; 1757 set->driver_data = NULL; 1758 1759 if (nullb->dev->blocking) ^^^^^^^^^^^^^^^^^^^^ And an unchecked dereference. nullb could be NULL here. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Shaohua Li <shli@fb.com> --- drivers/block/null_blk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)