From: Jan Kara <jack@suse.cz>
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 02/11] ext4: fix fiemap size checks for bitmap files
Date: Wed, 6 May 2020 11:18:02 +0200 [thread overview]
Message-ID: <20200506091802.GD17863@quack2.suse.cz> (raw)
In-Reply-To: <20200505154324.3226743-3-hch@lst.de>
On Tue 05-05-20 17:43:15, Christoph Hellwig wrote:
> Add an extra validation of the len parameter, as for ext4 some files
> might have smaller file size limits than others. This also means the
> redundant size check in ext4_ioctl_get_es_cache can go away, as all
> size checking is done in the shared fiemap handler.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Looks good to me. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> ---
> fs/ext4/extents.c | 31 +++++++++++++++++++++++++++++++
> fs/ext4/ioctl.c | 33 ++-------------------------------
> 2 files changed, 33 insertions(+), 31 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index f2b577b315a09..2b4b94542e34d 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -4832,6 +4832,28 @@ static const struct iomap_ops ext4_iomap_xattr_ops = {
> .iomap_begin = ext4_iomap_xattr_begin,
> };
>
> +static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len)
> +{
> + u64 maxbytes;
> +
> + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
> + maxbytes = inode->i_sb->s_maxbytes;
> + else
> + maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
> +
> + if (*len == 0)
> + return -EINVAL;
> + if (start > maxbytes)
> + return -EFBIG;
> +
> + /*
> + * Shrink request scope to what the fs can actually handle.
> + */
> + if (*len > maxbytes || (maxbytes - *len) < start)
> + *len = maxbytes - start;
> + return 0;
> +}
> +
> static int _ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> __u64 start, __u64 len, bool from_es_cache)
> {
> @@ -4852,6 +4874,15 @@ static int _ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> if (fiemap_check_flags(fieinfo, ext4_fiemap_flags))
> return -EBADR;
>
> + /*
> + * For bitmap files the maximum size limit could be smaller than
> + * s_maxbytes, so check len here manually instead of just relying on the
> + * generic check.
> + */
> + error = ext4_fiemap_check_ranges(inode, start, &len);
> + if (error)
> + return error;
> +
> if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
> fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
> error = iomap_fiemap(inode, fieinfo, start, len,
> diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
> index bfc1281fc4cbc..0746532ba463d 100644
> --- a/fs/ext4/ioctl.c
> +++ b/fs/ext4/ioctl.c
> @@ -733,29 +733,6 @@ static void ext4_fill_fsxattr(struct inode *inode, struct fsxattr *fa)
> fa->fsx_projid = from_kprojid(&init_user_ns, ei->i_projid);
> }
>
> -/* copied from fs/ioctl.c */
> -static int fiemap_check_ranges(struct super_block *sb,
> - u64 start, u64 len, u64 *new_len)
> -{
> - u64 maxbytes = (u64) sb->s_maxbytes;
> -
> - *new_len = len;
> -
> - if (len == 0)
> - return -EINVAL;
> -
> - if (start > maxbytes)
> - return -EFBIG;
> -
> - /*
> - * Shrink request scope to what the fs can actually handle.
> - */
> - if (len > maxbytes || (maxbytes - len) < start)
> - *new_len = maxbytes - start;
> -
> - return 0;
> -}
> -
> /* So that the fiemap access checks can't overflow on 32 bit machines. */
> #define FIEMAP_MAX_EXTENTS (UINT_MAX / sizeof(struct fiemap_extent))
>
> @@ -765,8 +742,6 @@ static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg)
> struct fiemap __user *ufiemap = (struct fiemap __user *) arg;
> struct fiemap_extent_info fieinfo = { 0, };
> struct inode *inode = file_inode(filp);
> - struct super_block *sb = inode->i_sb;
> - u64 len;
> int error;
>
> if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
> @@ -775,11 +750,6 @@ static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg)
> if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
> return -EINVAL;
>
> - error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
> - &len);
> - if (error)
> - return error;
> -
> fieinfo.fi_flags = fiemap.fm_flags;
> fieinfo.fi_extents_max = fiemap.fm_extent_count;
> fieinfo.fi_extents_start = ufiemap->fm_extents;
> @@ -792,7 +762,8 @@ static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg)
> if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
> filemap_write_and_wait(inode->i_mapping);
>
> - error = ext4_get_es_cache(inode, &fieinfo, fiemap.fm_start, len);
> + error = ext4_get_es_cache(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)))
> --
> 2.26.2
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2020-05-06 9:18 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 15:43 fix fiemap for ext4 bitmap files (+ cleanups) v3 Christoph Hellwig
2020-05-05 15:43 ` [PATCH 01/11] ext4: fix EXT4_MAX_LOGICAL_BLOCK macro Christoph Hellwig
2020-05-05 15:43 ` [PATCH 02/11] ext4: fix fiemap size checks for bitmap files Christoph Hellwig
2020-05-06 9:18 ` Jan Kara [this message]
2020-05-05 15:43 ` [PATCH 03/11] ext4: split _ext4_fiemap Christoph Hellwig
2020-05-06 9:22 ` Jan Kara
2020-05-05 15:43 ` [PATCH 04/11] ext4: remove the call to fiemap_check_flags in ext4_fiemap Christoph Hellwig
2020-05-06 9:26 ` Jan Kara
2020-05-05 15:43 ` [PATCH 05/11] fs: mark __generic_block_fiemap static Christoph Hellwig
2020-05-06 9:27 ` Jan Kara
2020-05-05 15:43 ` [PATCH 06/11] fs: move the fiemap definitions out of fs.h Christoph Hellwig
2020-05-05 15:43 ` [PATCH 07/11] iomap: fix the iomap_fiemap prototype Christoph Hellwig
2020-05-05 15:43 ` [PATCH 08/11] fs: move fiemap range validation into the file systems instances Christoph Hellwig
2020-05-05 16:01 ` Darrick J. Wong
2020-05-06 4:16 ` Ritesh Harjani
2020-05-05 15:43 ` [PATCH 09/11] fs: handle FIEMAP_FLAG_SYNC in fiemap_prep Christoph Hellwig
2020-05-06 4:17 ` Ritesh Harjani
2020-05-05 15:43 ` [PATCH 10/11] fs: remove the access_ok() check in ioctl_fiemap Christoph Hellwig
2020-05-05 15:43 ` [PATCH 11/11] ext4: remove the access_ok() check in ext4_ioctl_get_es_cache Christoph Hellwig
2020-05-06 9:32 ` Jan Kara
2020-05-07 6:24 ` fix fiemap for ext4 bitmap files (+ cleanups) v3 Christoph Hellwig
2020-05-07 14:49 ` Theodore Y. Ts'o
2020-05-07 14:59 ` Christoph Hellwig
2020-05-19 8:04 ` Christoph Hellwig
2020-05-20 3:28 ` Theodore Y. Ts'o
2020-05-22 0:00 ` Linus Torvalds
2020-05-22 6:35 ` Christoph Hellwig
-- strict thread matches above, loose matches on Subject: below --
2020-04-27 18:19 fix fiemap for ext4 bitmap files (+ cleanups) v2 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
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