Commit 3078d85c authored Dec 14, 2020 by Miklos Szeredi

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>

parent 7c03e2cd

fs/remap_range.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -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;