vfs: verify source area in vfs_dedupe_file_range_one()

Call remap_verify_area() on the source file as well as the destination.

When called from vfs_dedupe_file_range() the check as already been
performed, but not so if called from layered fs (overlayfs, etc...)

Could ommit the redundant check in vfs_dedupe_file_range(), but leave for
now to get error early (for fear of breaking backward compatibility).

This call shouldn't be performance sensitive.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Miklos Szeredi 2020-12-14 15:26:13 +01:00
parent 7c03e2cda4
commit 3078d85c9a

View File

@ -456,8 +456,16 @@ loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
if (ret)
return ret;
/*
* This is redundant if called from vfs_dedupe_file_range(), but other
* callers need it and it's not performance sesitive...
*/
ret = remap_verify_area(src_file, src_pos, len, false);
if (ret)
goto out_drop_write;
ret = remap_verify_area(dst_file, dst_pos, len, true);
if (ret < 0)
if (ret)
goto out_drop_write;
ret = -EPERM;