[PATCH v5] block: add check that partition length needs to be aligned with block size

[PATCH v5] block: add check that partition length needs to be aligned with block size

[Min Li]

Before calling add partition or resize partition, there is no check
on whether the length is aligned with the logical block size.
If the logical block size of the disk is larger than 512 bytes,
then the partition size maybe not the multiple of the logical block size,
and when the last sector is read, bio_truncate() will adjust the bio size,
resulting in an IO error if the size of the read command is smaller than
the logical block size.If integrity data is supported, this will also
result in a null pointer dereference when calling bio_integrity_free.

Cc: stable@vger.kernel.org
Signed-off-by: Min Li <min15.li@samsung.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

---
Changes from v1:

- Add a space after /* and before */.
- Move length alignment check before the "start = p.start >> SECTOR_SHIFT"
- Move check for p.start being aligned together with this length alignment check.

Changes from v2:

- Add the assignment on the first line and merge the two lines into one.

Changes from v3:

- Change the blksz to unsigned int.
- Add check if p.start and p.length are negative.

Changes from v4:

- Remove the local variable blksz and use bdev_logical_block_size(bdev) directly.
---
 block/ioctl.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/block/ioctl.c b/block/ioctl.c
index 3be11941fb2d..0e8723c1a807 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -18,7 +18,7 @@ static int blkpg_do_ioctl(struct block_device *bdev,
 {
 	struct gendisk *disk = bdev->bd_disk;
 	struct blkpg_partition p;
-	long long start, length;
+	sector_t start, length;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
@@ -33,14 +33,17 @@ static int blkpg_do_ioctl(struct block_device *bdev,
 	if (op == BLKPG_DEL_PARTITION)
 		return bdev_del_partition(disk, p.pno);
 
+	if (p.start < 0 || p.length <= 0 || p.start + p.length < 0)
+		return -EINVAL;
+	/* Check that the partition is aligned to the block size */
+	if (!IS_ALIGNED(p.start | p.length, bdev_logical_block_size(bdev)))
+		return -EINVAL;
+
 	start = p.start >> SECTOR_SHIFT;
 	length = p.length >> SECTOR_SHIFT;
 
 	switch (op) {
 	case BLKPG_ADD_PARTITION:
-		/* check if partition is aligned to blocksize */
-		if (p.start & (bdev_logical_block_size(bdev) - 1))
-			return -EINVAL;
 		return bdev_add_partition(disk, p.pno, start, length);
 	case BLKPG_RESIZE_PARTITION:
 		return bdev_resize_partition(disk, p.pno, start, length);
-- 
2.34.1

Re: [PATCH v5] block: add check that partition length needs to be aligned with block size

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH v5] block: add check that partition length needs to be aligned with block size

[Min Li]

Thanks

Min li

Re: [PATCH v5] block: add check that partition length needs to be aligned with block size

[Li Nan]

friendly ping ...

在 2023/10/16 22:03, Min Li 写道:
> Thanks
> 
> Min li
> .

-- 
Thanks,
Nan

Re: [PATCH v5] block: add check that partition length needs to be aligned with block size

[Jens Axboe]

On Thu, 29 Jun 2023 14:25:17 +0000, Min Li wrote:
> Before calling add partition or resize partition, there is no check
> on whether the length is aligned with the logical block size.
> If the logical block size of the disk is larger than 512 bytes,
> then the partition size maybe not the multiple of the logical block size,
> and when the last sector is read, bio_truncate() will adjust the bio size,
> resulting in an IO error if the size of the read command is smaller than
> the logical block size.If integrity data is supported, this will also
> result in a null pointer dereference when calling bio_integrity_free.
> 
> [...]

Applied, thanks!

[1/1] block: add check that partition length needs to be aligned with block size
      commit: 6f64f866aa1ae6975c95d805ed51d7e9433a0016

Best regards,
-- 
Jens Axboe