From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-ext4@vger.kernel.org, viro@zeniv.linux.org.uk,
jack@suse.cz, tytso@mit.edu, adilger@dilger.ca,
riteshh@linux.ibm.com, amir73il@gmail.com,
linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org
Subject: Re: [PATCH 10/11] fs: remove the access_ok() check in ioctl_fiemap
Date: Tue, 28 Apr 2020 08:21:24 -0700 [thread overview]
Message-ID: <20200428152124.GL6741@magnolia> (raw)
In-Reply-To: <20200427181957.1606257-11-hch@lst.de>
On Mon, Apr 27, 2020 at 08:19:56PM +0200, Christoph Hellwig wrote:
> access_ok just checks we are fed a proper user pointer. We also do that
> in copy_to_user itself, so no need to do this early.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
Hmm. It's a minor behavioral change that we no longer require the
entire extent array to be accessible at the start even if parts of it
would never have gotten accessed, but I don't think that matters, so:
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
--D
> ---
> fs/ioctl.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/fs/ioctl.c b/fs/ioctl.c
> index ae0d228d18a16..d24afce649037 100644
> --- a/fs/ioctl.c
> +++ b/fs/ioctl.c
> @@ -209,13 +209,9 @@ static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
> fieinfo.fi_extents_max = fiemap.fm_extent_count;
> fieinfo.fi_extents_start = ufiemap->fm_extents;
>
> - if (fiemap.fm_extent_count != 0 &&
> - !access_ok(fieinfo.fi_extents_start,
> - fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
> - return -EFAULT;
> -
> error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start,
> fiemap.fm_length);
> +
> fiemap.fm_flags = fieinfo.fi_flags;
> fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
> if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
> --
> 2.26.1
>
next prev parent reply other threads:[~2020-04-28 15:23 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-27 18:19 fix fiemap for ext4 bitmap files (+ cleanups) v2 Christoph Hellwig
2020-04-27 18:19 ` [PATCH 01/11] ext4: fix EXT4_MAX_LOGICAL_BLOCK macro Christoph Hellwig
2020-04-27 18:19 ` [PATCH 02/11] ext4: fix fiemap size checks for bitmap files Christoph Hellwig
2020-05-01 23:20 ` Ritesh Harjani
2020-04-27 18:19 ` [PATCH 03/11] ext4: split _ext4_fiemap Christoph Hellwig
2020-05-01 23:21 ` Ritesh Harjani
2020-04-27 18:19 ` [PATCH 04/11] ext4: remove the call to fiemap_check_flags in ext4_fiemap Christoph Hellwig
2020-05-01 23:21 ` Ritesh Harjani
2020-04-27 18:19 ` [PATCH 05/11] fs: mark __generic_block_fiemap static Christoph Hellwig
2020-04-28 15:06 ` Darrick J. Wong
2020-05-01 23:22 ` Ritesh Harjani
2020-04-27 18:19 ` [PATCH 06/11] fs: move the fiemap definitions out of fs.h Christoph Hellwig
2020-04-28 15:07 ` Darrick J. Wong
2020-05-01 23:23 ` Ritesh Harjani
2020-04-27 18:19 ` [PATCH 07/11] iomap: fix the iomap_fiemap prototype Christoph Hellwig
2020-04-28 15:08 ` Darrick J. Wong
2020-05-01 23:34 ` Ritesh Harjani
2020-05-05 10:29 ` Christoph Hellwig
2020-04-27 18:19 ` [PATCH 08/11] fs: move fiemap range validation into the file systems instances Christoph Hellwig
2020-04-28 2:35 ` Amir Goldstein
2020-04-28 15:14 ` Darrick J. Wong
2020-05-01 22:49 ` Ritesh Harjani
2020-05-05 10:37 ` Christoph Hellwig
2020-04-27 18:19 ` [PATCH 09/11] fs: handle FIEMAP_FLAG_SYNC in fiemap_prep Christoph Hellwig
2020-04-28 2:26 ` Amir Goldstein
2020-04-28 15:16 ` Darrick J. Wong
2020-05-01 22:52 ` Ritesh Harjani
2020-05-05 10:43 ` Christoph Hellwig
2020-04-27 18:19 ` [PATCH 10/11] fs: remove the access_ok() check in ioctl_fiemap Christoph Hellwig
2020-04-28 15:21 ` Darrick J. Wong [this message]
2020-05-05 10:44 ` Christoph Hellwig
2020-05-01 22:56 ` Ritesh Harjani
2020-04-27 18:19 ` [PATCH 11/11] ext4: remove the access_ok() check in ext4_ioctl_get_es_cache Christoph Hellwig
2020-05-01 22:56 ` Ritesh Harjani
2020-05-05 15:43 fix fiemap for ext4 bitmap files (+ cleanups) v3 Christoph Hellwig
2020-05-05 15:43 ` [PATCH 10/11] fs: remove the access_ok() check in ioctl_fiemap Christoph Hellwig
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