在 2024/9/17 15:07, Aleksandr Mishin 写道:
In null_alloc_dev() device size is a subject to overflow because 'g_gb'
(which is module parameter, may have any value and is not validated
anywhere) is not cast to a larger data type before performing arithmetic.
Cast 'g_gb' to unsigned long to prevent overflow.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 2984c8684f96 ("nullb: factor disk parameters")
Signed-off-by: Aleksandr Mishin <amishin@xxxxxxxxxx>
---
drivers/block/null_blk/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 2f0431e42c49..5edbf9c0aceb 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -762,7 +762,7 @@ static struct nullb_device *null_alloc_dev(void)
return NULL;
}
- dev->size = g_gb * 1024;
The member variable size in struct nullb_device is type "unsigned long".
As such, changing g_gb from int to "unsigned long" seems reasonable.
So I am fine with this.
Reviewed-by: Zhu Yanjun <yanjun.zhu@xxxxxxxxx>
Thanks a lot.
Zhu Yanjun
+ dev->size = (unsigned long)g_gb * 1024;
dev->completion_nsec = g_completion_nsec;
dev->submit_queues = g_submit_queues;
dev->prev_submit_queues = g_submit_queues;
--
Best Regards,
Yanjun.Zhu
