2018-07-31 18:26:20

by Khazhismel Kumykov

[permalink] [raw]
Subject: Re: [PATCH] block/compat_ioctl: fix range check in BLKGETSIZE

Ping?

On Fri, Apr 6, 2018 at 3:23 PM, Khazhismel Kumykov <[email protected]> wrote:
> 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.
>
> Signed-off-by: Khazhismel Kumykov <[email protected]>
> ---
> block/compat_ioctl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
> index 6ca015f92766..3a2c77f07da8 100644
> --- a/block/compat_ioctl.c
> +++ b/block/compat_ioctl.c
> @@ -388,7 +388,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
> return 0;
> case BLKGETSIZE:
> size = i_size_read(bdev->bd_inode);
> - if ((size >> 9) > ~0UL)
> + if ((size >> 9) > ~((compat_ulong_t)0UL))
> return -EFBIG;
> return compat_put_ulong(arg, size >> 9);
>
> --
> 2.17.0.484.g0c8726318c-goog
>


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2018-08-02 21:33:01

by Jens Axboe

[permalink] [raw]
Subject: Re: [PATCH] block/compat_ioctl: fix range check in BLKGETSIZE

On 4/6/18 4:23 PM, Khazhismel Kumykov wrote:
> 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.

Sorry for not getting to this. Applied, thanks.

--
Jens Axboe