[material-ui][Dialog] Broken scrolling in fullScreen dialogs (v6)

[federico-ntr]

Steps to reproduce

Link to live example: https://codesandbox.io/s/wizardly-swirles-yw2t4t?file=/src/Demo.js
Steps:

1. Open repro
2. Adjust the number of list items in the dialog if you don't have enough items to fill the height of the dialog
3. Try to scroll

PS: repro is actually the example from the docs with more list items quickly copy-pasted to overflow the screen vertically

Current behavior

Scrolling doesn't work unless you manually target the element and add scrolling through CSS

Expected behavior

Scrolling should work with no additional steps, or at least there should be a sort of statement in the docs.

Context

This is one of the actually few things that broke while upgrading to v6.

Your environment

npx @mui/envinfo

  System:
    OS: macOS 14.6.1
  Binaries:
    Node: 22.6.0 - ~/.nvm/versions/node/v22.6.0/bin/node
    npm: 10.8.2 - ~/.nvm/versions/node/v22.6.0/bin/npm
    pnpm: Not Found
  Browsers:
    Chrome: 128.0.6613.113
    Edge: 128.0.2739.54
    Safari: 17.6
  npmPackages:
    @emotion/react: 11.13.3 => 11.13.3 
    @emotion/styled: 11.13.0 => 11.13.0 
    @mui/base:  5.0.0-beta.40 
    @mui/core-downloads-tracker:  6.0.1 
    @mui/icons-material: 6.0.1 => 6.0.1 
    @mui/lab: 5.0.0-alpha.173 => 5.0.0-alpha.173 
    @mui/material: 6.0.1 => 6.0.1 
    @mui/private-theming:  5.16.5 
    @mui/styled-engine:  5.16.4 
    @mui/system: 6.0.1 => 6.0.1 
    @mui/types:  7.2.15 
    @mui/utils:  5.16.5 
    @mui/x-data-grid: 7.15.0 => 7.15.0 
    @mui/x-date-pickers: 7.15.0 => 7.15.0 
    @mui/x-internals:  7.15.0 
    @types/react: 18.3.5 => 18.3.5 
    react: 18.3.1 => 18.3.1 
    react-dom: 18.3.1 => 18.3.1 
    typescript: 5.5.4 => 5.5.4 ```
</details>


**Search keywords**: broken scrolling fullscreen dialog

[ZeeshanTamboli]

It's a regression from #42283 where we removed overflowY: 'auto' from the Dialog's paper component (see #42283 (comment)). Adding it back fixes the issue.

[LuseBiswas]

Hello @ZeeshanTamboli I think I had fixed the issue of it. Can you please assing this issue to me.

[DiegoAndai]

@LuseBiswas thanks for reaching out, if you want please open a PR with the fix and add me as a reviewer, otherwise I'll open a PR tomorrow.

[LuseBiswas]

@DiegoAndai kindly review my code.
Actually I am new to Open Source Contribution so I dont know how add a reviewer. So I am doing it mannualy.

[github-actions]

This issue has been closed. If you have a similar problem but not exactly the same, please open a new issue.
Now, if you have additional information related to this issue or things that could help future readers, feel free to leave a comment.

Note

We value your feedback @federico-ntr! How was your experience with our support team?
If you could spare a moment, we'd love to hear your thoughts in this brief Support Satisfaction survey. Your insights help us improve!

[oliviertassinari]

@ZeeshanTamboli #43572 (comment) nice hunting this down 👍