From ccf16413e520164eb718cf8b22a30438da80ff23 Mon Sep 17 00:00:00 2001
From: Khazhismel Kumykov <khazhy@google.com>
Date: Thu, 14 Apr 2022 15:40:56 -0700
Subject: block/compat_ioctl: fix range check in BLKGETSIZE

From: Khazhismel Kumykov <khazhy@google.com>

commit ccf16413e520164eb718cf8b22a30438da80ff23 upstream.

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: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220414224056.2875681-1-khazhy@google.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 block/ioctl.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -629,7 +629,7 @@ long compat_blkdev_ioctl(struct file *fi
 		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));