Description

The spacing block support allows the user to enter arbitrarily large values for padding, which does not respect width or max-width set on the block and can cause the block to overflow the page.

Step-by-step reproduction instructions

1. Create a new post and insert a Cover block.
2. In the Inspector Controls, open the Spacing panel, enter a very large number in the Padding input (99999), and hit Enter.

Expected behaviour

The block should not exceed the width of the page.

Actual behaviour

There is no maximum amount of padding, and the block becomes extremely large and overflows the page.

Screenshots or screen recording (optional)

_Note the horizontal scrollbar._

Code snippet (optional)

WordPress information

• WordPress version: 5.7.1
• Gutenberg version: trunk
• Are all plugins except Gutenberg deactivated? Yes
• Are you using a default theme (e.g. Twenty Twenty-One)? Yes

Device information

• Device: Desktop
• Operating system: Mac Big Sur
• Browser: Chrome 90