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 <min15.li@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230619091214.31615-1-min15.li@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 87a21942d60667acdc6a78c12d25feb9cafe58f1..13a7341299a9134de2c17d00020d3475d397f2cf 100644 (file)
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -441,10 +441,21 @@ 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;