diff mbox series

[4/5] overlayfs: Check for range bounds before calling i_op->fiemap()

Message ID 39b4bf94f6723831a9798237bb1b4ae14da04d98.1587555962.git.riteshh@linux.ibm.com
State New
Headers show
Series ext4/overlayfs: fiemap related fixes | expand

Commit Message

Ritesh Harjani April 23, 2020, 10:47 a.m. UTC
Underlying fs may not be able to handle the length in fiemap
beyond sb->s_maxbytes. So similar to how VFS ioctl does it,
add fiemap_check_ranges() check in ovl_fiemap() as well
before calling underlying fs i_op->fiemap() call.

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
---
 fs/overlayfs/inode.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Jan Kara April 23, 2020, 11:19 a.m. UTC | #1
On Thu 23-04-20 16:17:56, Ritesh Harjani wrote:
> Underlying fs may not be able to handle the length in fiemap
> beyond sb->s_maxbytes. So similar to how VFS ioctl does it,
> add fiemap_check_ranges() check in ovl_fiemap() as well
> before calling underlying fs i_op->fiemap() call.
> 
> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
> ---
>  fs/overlayfs/inode.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)

Yeah, makes sense. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> 
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index 79e8994e3bc1..9bcd2e96faad 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -455,16 +455,21 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
>  	int err;
>  	struct inode *realinode = ovl_inode_real(inode);
>  	const struct cred *old_cred;
> +	u64 length;
>  
>  	if (!realinode->i_op->fiemap)
>  		return -EOPNOTSUPP;
>  
> +	err = fiemap_check_ranges(realinode->i_sb, start, len, &length);
> +	if (err)
> +		return err;
> +
>  	old_cred = ovl_override_creds(inode->i_sb);
>  
>  	if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
>  		filemap_write_and_wait(realinode->i_mapping);
>  
> -	err = realinode->i_op->fiemap(realinode, fieinfo, start, len);
> +	err = realinode->i_op->fiemap(realinode, fieinfo, start, length);
>  	revert_creds(old_cred);
>  
>  	return err;
> -- 
> 2.21.0
>
Amir Goldstein April 25, 2020, 8:54 a.m. UTC | #2
On Thu, Apr 23, 2020 at 1:48 PM Ritesh Harjani <riteshh@linux.ibm.com> wrote:
>
> Underlying fs may not be able to handle the length in fiemap
> beyond sb->s_maxbytes. So similar to how VFS ioctl does it,
> add fiemap_check_ranges() check in ovl_fiemap() as well
> before calling underlying fs i_op->fiemap() call.
>
> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
> ---
>  fs/overlayfs/inode.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index 79e8994e3bc1..9bcd2e96faad 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -455,16 +455,21 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
>         int err;
>         struct inode *realinode = ovl_inode_real(inode);
>         const struct cred *old_cred;
> +       u64 length;

To be more clear, I would call that reallen, but apart from that, you may add:

Reviewed-by: Amir Goldstein <amir73il@gmail.com>

Thanks,
Amir.
diff mbox series

Patch

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 79e8994e3bc1..9bcd2e96faad 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -455,16 +455,21 @@  static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	int err;
 	struct inode *realinode = ovl_inode_real(inode);
 	const struct cred *old_cred;
+	u64 length;
 
 	if (!realinode->i_op->fiemap)
 		return -EOPNOTSUPP;
 
+	err = fiemap_check_ranges(realinode->i_sb, start, len, &length);
+	if (err)
+		return err;
+
 	old_cred = ovl_override_creds(inode->i_sb);
 
 	if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
 		filemap_write_and_wait(realinode->i_mapping);
 
-	err = realinode->i_op->fiemap(realinode, fieinfo, start, len);
+	err = realinode->i_op->fiemap(realinode, fieinfo, start, length);
 	revert_creds(old_cred);
 
 	return err;