2023-06-16 07:45:01

by Min Li

Subject: [PATCH v2] block: add capacity validation in bdev_add_partition()

In the function bdev_add_partition(),there is no check that the start
and end sectors exceed the size of the disk before calling add_partition.
When we call the block's ioctl interface directly to add a partition,
and the capacity of the disk is set to 0 by driver,the command will
continue to execute.
v1->v2: check for overflows of the start + length value and put
the capacity check at the beginning of the function.

Signed-off-by: min15.li <[email protected]>
---
block/partitions/core.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 49e0496ff23c..3546b43d5124 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -438,8 +438,20 @@ int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
{
struct block_device *part;
int ret;
+ sector_t end;
+ sector_t capacity = get_capacity(disk);

mutex_lock(&disk->open_mutex);
+ if (check_add_overflow(start, length, &end)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (start >= capacity || end > capacity) {
+ ret = -EINVAL;
+ goto out;
+ }
+
if (!disk_live(disk)) {
ret = -ENXIO;
goto out;
--
2.34.1

2023-06-16 08:10:37

by Greg Kroah-Hartman

Subject: Re: [PATCH v2] block: add capacity validation in bdev_add_partition()

On Fri, Jun 16, 2023 at 11:05:57AM +0000, min15.li wrote:
> In the function bdev_add_partition(),there is no check that the start
> and end sectors exceed the size of the disk before calling add_partition.
> When we call the block's ioctl interface directly to add a partition,
> and the capacity of the disk is set to 0 by driver,the command will
> continue to execute.
> v1->v2: check for overflows of the start + length value and put
> the capacity check at the beginning of the function.
>
> Signed-off-by: min15.li <[email protected]>

I doubt you sign documents as "min15.li", right? :)

Please fix.

You also forgot a "changes" list below the --- line saying what changed
from the previous submission.

thanks,

greg k-h