2023-06-26 10:11:37

by Min Li

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

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.

Signed-off-by: Min Li <[email protected]>
---
block/ioctl.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/block/ioctl.c b/block/ioctl.c
index 9c5f637ff153..aa95b5561169 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -35,6 +35,9 @@ static int blkpg_do_ioctl(struct block_device *bdev,

start = p.start >> SECTOR_SHIFT;
length = p.length >> SECTOR_SHIFT;
+ /*check if length is aligned to blocksize*/
+ if (p.length & (bdev_logical_block_size(bdev) - 1))
+ return -EINVAL;

switch (op) {
case BLKPG_ADD_PARTITION:
--
2.34.1

2023-06-26 10:22:40

by Damien Le Moal

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

On 6/27/23 02:10, 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.
>
> Signed-off-by: Min Li <[email protected]>
> ---
> block/ioctl.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/block/ioctl.c b/block/ioctl.c
> index 9c5f637ff153..aa95b5561169 100644
> --- a/block/ioctl.c
> +++ b/block/ioctl.c
> @@ -35,6 +35,9 @@ static int blkpg_do_ioctl(struct block_device *bdev,
>
> start = p.start >> SECTOR_SHIFT;
> length = p.length >> SECTOR_SHIFT;
> + /*check if length is aligned to blocksize*/

Please add a space after /* and before */.

> + if (p.length & (bdev_logical_block_size(bdev) - 1))
> + return -EINVAL;

I would move this check before the "start = ...;" And while at it, I would also
move the check for p.start being aligned out of the "case BLKPG_ADD_PARTITION:"
together with this length alignment check. The p.start check is not needed for
BLKPG_RESIZE_PARTITION, but it will not hurt either.

>
> switch (op) {
> case BLKPG_ADD_PARTITION:

--
Damien Le Moal
Western Digital Research

2023-06-26 14:54:51

by Greg Kroah-Hartman

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

On Mon, Jun 26, 2023 at 05:10:21PM +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.
>
> Signed-off-by: Min Li <[email protected]>

What commit id does this fix?

thanks,

greg k-h