On 3/5/24 15:24, Li Lingfeng wrote:
>
> 在 2024/3/5 12:30, Damien Le Moal 写道:
>> On 3/5/24 12:21, Li Lingfeng wrote:
>>> From: Li Lingfeng <lilingfeng3@xxxxxxxxxx>
>>>
>>> Commit 6d4e80db4ebe ("block: add capacity validation in
>>> bdev_add_partition()") add check of partition's start and end sectors to
>>> prevent exceeding the size of the disk when adding partitions. However,
>>> there is still no check for resizing partitions now.
>>> Move the check to blkpg_do_ioctl() to cover resizing partitions.
>>>
>>> Signed-off-by: Li Lingfeng <lilingfeng3@xxxxxxxxxx>
>>> ---
>>> block/ioctl.c | 9 ++++++++-
>>> block/partitions/core.c | 11 -----------
>>> 2 files changed, 8 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/block/ioctl.c b/block/ioctl.c
>>> index 438f79c564cf..de0cc0d215c6 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;
>>> - sector_t start, length;
>>> + sector_t start, length, capacity, end;
>>> if (!capable(CAP_SYS_ADMIN))
>>> return -EACCES;
>>> @@ -41,6 +41,13 @@ static int blkpg_do_ioctl(struct block_device *bdev,
>>> start = p.start >> SECTOR_SHIFT;
>>> length = p.length >> SECTOR_SHIFT;
>>> + capacity = get_capacity(disk);
>>> +
>>> + if (check_add_overflow(start, length, &end))
>>> + return -EINVAL;
>>> +
>>> + if (start >= capacity || end > capacity)
>>> + return -EINVAL;
>>> switch (op) {
>>> case BLKPG_ADD_PARTITION:
>>> diff --git a/block/partitions/core.c b/block/partitions/core.c
>>> index 5f5ed5c75f04..b11e88c82c8c 100644
>>> --- a/block/partitions/core.c
>>> +++ b/block/partitions/core.c
>>> @@ -419,21 +419,10 @@ 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;
>>> - }
>>> -
>> Why do you remove this ? The check will not be done when *existing* partitions
> I'm sorry, I didn't quite understand your point. The function
> bdev_add_partition() is only called within blkpg_do_ioctl(). I simply moved the
> check to a different location, but did not remove it entirely.
Oh ! My bad ! I got confused with blk_add_partition() which is the function
adding partitions when a new disk is scanned. So yes, your patch is fine. My
apologies for the noise.
>> are added. To do the check when *creating* a partition, make this code a helper
>> and call that helper function here and from blkpg_do_ioctl() as well.
> Do you mean call the helper function in blk_add_partition() and blkpg_do_ioctl()?
>>
>>> if (!disk_live(disk)) {
>>> ret = -ENXIO;
>>> goto out;
>
>
--
Damien Le Moal
Western Digital Research
