2023-06-15 09:05:25

by Min Li

Subject: [PATCH] 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.

Signed-off-by: min15.li <[email protected]>
---
block/partitions/core.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 49e0496ff23c..9806a804e1a4 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -445,6 +445,12 @@ int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
goto out;
}

+ if (start >= get_capacity(disk) ||
+ start + length > get_capacity(disk)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
if (partition_overlaps(disk, start, length, -1)) {
ret = -EBUSY;
goto out;
--
2.34.1

2023-06-15 09:06:15

by Christoph Hellwig

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

On Thu, Jun 15, 2023 at 04:09:29PM +0000, min15.li wrote:
> + if (start >= get_capacity(disk) ||
> + start + length > get_capacity(disk)) {

We need to check for overflows of the start + length value,
probably best using a helper like check_add_overflow.

Also a single tab indent (and thus the same as code below) is always
wrong for continuations, plase use either two tabs or align to the
opening brace.