2023-06-16 09:45:21

by Min Li

Subject: [PATCH v3] 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: min.li <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>

---
Changes from v1:

- Check for overflows of the start + length value.
- Place the capacity check at the beginning of the function.

Changes from v2:

- Place the assignment on the first line and merge the two lines into one.
- Modify the singed name.
---
block/partitions/core.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 49e0496ff23c..b511f88bf558 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -436,10 +436,21 @@ static bool partition_overlaps(struct gendisk *disk, sector_t start,
int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
sector_t length)
{
+ sector_t capacity = get_capacity(disk), end;
struct block_device *part;
int ret;

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 12:03:50

by Damien Le Moal

Subject: Re: [PATCH v3] block: add capacity validation in bdev_add_partition()

On 6/17/23 02:19, min.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.
>
> Signed-off-by: min.li <[email protected]>

I am guessing this should be:

Signed-off-by: Min Li <[email protected]>

No ? The signed-off-by tag, and any other tag, must have your full name
correctly written.

> Reviewed-by: Christoph Hellwig <[email protected]>
>
> ---
> Changes from v1:
>
> - Check for overflows of the start + length value.
> - Place the capacity check at the beginning of the function.
>
> Changes from v2:
>
> - Place the assignment on the first line and merge the two lines into one.
> - Modify the singed name.
> ---
> block/partitions/core.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/block/partitions/core.c b/block/partitions/core.c
> index 49e0496ff23c..b511f88bf558 100644
> --- a/block/partitions/core.c
> +++ b/block/partitions/core.c
> @@ -436,10 +436,21 @@ static bool partition_overlaps(struct gendisk *disk, sector_t start,
> int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
> sector_t length)
> {
> + sector_t capacity = get_capacity(disk), end;
> struct block_device *part;
> int ret;
>
> 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;

--
Damien Le Moal
Western Digital Research