Commit ccf16413 authored by Khazhismel Kumykov's avatar Khazhismel Kumykov Committed by Jens Axboe
Browse files

block/compat_ioctl: fix range check in BLKGETSIZE 



kernel ulong and compat_ulong_t may not be same width. Use type directly
to eliminate mismatches.

This would result in truncation rather than EFBIG for 32bit mode for
large disks.

Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarKhazhismel Kumykov <khazhy@google.com>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220414224056.2875681-1-khazhy@google.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3e3876d3

block/ioctl.c

+1 −1
Original line number Diff line number Diff line
@@ -629,7 +629,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) 
		return compat_put_long(argp,

			(bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512);

	case BLKGETSIZE:

		if (bdev_nr_sectors(bdev) > ~0UL)

		if (bdev_nr_sectors(bdev) > ~(compat_ulong_t)0)

			return -EFBIG;

		return compat_put_ulong(argp, bdev_nr_sectors(bdev));