On 6/29/23 19:26, 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.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Min Li <min15.li@xxxxxxxxxxx>>
> ---
> 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.
> ---
> block/ioctl.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/block/ioctl.c b/block/ioctl.c
> index 3be11941fb2d..a8061c2fcae0 100644
> --- a/block/ioctl.c
> +++ b/block/ioctl.c
> @@ -16,9 +16,10 @@
> static int blkpg_do_ioctl(struct block_device *bdev,
> struct blkpg_partition __user *upart, int op)
> {
> + unsigned int blksz = bdev_logical_block_size(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 +34,17 @@ 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, blksz))
Minor nit: blksz is used only here now, so this could be changed to:
if (!IS_ALIGNED(p.start | p.length, bdev_logical_block_size(bdev)))
to not use that local variable.
With or without this addressed, looks good to me.
Reviewed-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
> + 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);
--
Damien Le Moal
Western Digital Research
