diff mbox series

[v5.15] block/compat_ioctl: fix range check in BLKGETSIZE

Message ID 20220425192740.171756-2-khazhy@google.com
State New
Headers show
Series [v5.15] block/compat_ioctl: fix range check in BLKGETSIZE | expand

Commit Message

Khazhismel Kumykov April 25, 2022, 7:27 p.m. UTC 
[ Upstream commit ccf16413e520164eb718cf8b22a30438da80ff23 ]

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>
---
 block/ioctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/block/ioctl.c b/block/ioctl.c
index a31be7fa31a5..cd506a902963 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -645,7 +645,7 @@  long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 			(bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512);
 	case BLKGETSIZE:
 		size = i_size_read(bdev->bd_inode);
-		if ((size >> 9) > ~0UL)
+		if ((size >> 9) > ~(compat_ulong_t)0)
 			return -EFBIG;
 		return compat_put_ulong(argp, size >> 9);