1449864 - [snap package] removable-media plug needed to allow saving downloaded files to /media

Status: RESOLVED FIXED

(Release Engineering :: Release Automation: Other, defect)

Description

[Olivier Tilloy]

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/66.0.3359.45 Chrome/66.0.3359.45 Safari/537.36

Steps to reproduce:

As initially reported at https://forum.snapcraft.io/t/snap-firefox-unable-to-save-downloads-files/4734, firefox installed from the snap package doesn't allow saving downloaded files to /media.

Steps to reproduce:
 snap install firefox
 /snap/bin/firefox
 browse to e.g. https://kernel.org, right-click on a [tarball] link and choose "Save Link As…"
 in the file dialog, try browsing to /media


Actual results:

An error dialog pops up: « Error opening directory '/media': Permission denied »


Expected results:

The user can browse to /media and subdirectories, and choose to save the file there.

Comment 1

[Olivier Tilloy]

Attachment: Bug 1449864: [snap package] add the removable-media plug to allow saving downloaded files to /media.

Review commit: https://reviewboard.mozilla.org/r/232446/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/232446/

Comment 2

[jlorenzo (disabled)]

Comment on attachment 8963501 [details]
Bug 1449864: [snap package] add the removable-media plug to allow saving downloaded files to /media.

https://reviewboard.mozilla.org/r/232446/#review238718

This makes sense to me. Thank you for the investigation and the fix!

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d3bbcd354714
[snap package] add the removable-media plug to allow saving downloaded files to /media. r=jlorenzo

Comment 4

[jlorenzo (disabled)]

Comment on attachment 8963501 [details]
Bug 1449864: [snap package] add the removable-media plug to allow saving downloaded files to /media.

Approval Request Comment
[Feature/Bug causing the regression]: None
[User impact if declined]: Linux: Can't download on external devices.
[Is this code covered by automated tests?]: No.
[Has the fix been verified in Nightly?]: N/A. We don't build snaps on Nigthly.
[Needs manual test from QE? If yes, steps to reproduce]: No. Tests were done by partner.
[List of other uplifts needed for the feature/fix]: None
[Is the change risky?]: No
[Why is the change risky/not risky?]: This adds a new permission to the security model of Snap packages.
[String changes made/needed]: None.

Comment 5

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/d3bbcd354714

Comment 6

[Kestrel]

Unfortunately /media is not just used by removable media, Nautilus File Manager automatically mounts additional drive partitions there, making any Windows partitions fully exposed. Fortunately the user can revoke access with:

> sudo snap disconnect firefox:removable-media

Comment 7

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 8963501 [details]
Bug 1449864: [snap package] add the removable-media plug to allow saving downloaded files to /media.

Not ready for uplift.

Comment 8

[jlorenzo (disabled)]

Comment 6 seems like an important security issue. What's your take on this, Olivier?

Comment 9

[Kestrel]

It appears the removable-media interface does _not_ auto-connect by default, the user must do this manually. Sorry for the confusion.

Comment 10

[Olivier Tilloy]

That's right, the removable-media plug is not auto-connected, it's a manual operation. So that doesn't open any security hole by default.

Comment 11

[jlorenzo (disabled)]

I can't set the approval-mozilla-beta flag back to "?". Could you set it for me, Ryan?

Comment 12

[Julien Cristau [:jcristau]]

Comment on attachment 8963501 [details]
Bug 1449864: [snap package] add the removable-media plug to allow saving downloaded files to /media.

Sounds fine.  approved for 60.0b14.

Comment 13

[jlorenzo (disabled)]

https://hg.mozilla.org/releases/mozilla-beta/rev/d886178ae9a02b3d165c30411ffe574e1972f845

Comment 14

[jlorenzo (disabled)]

Follow up work on the snapd-side: https://forum.snapcraft.io/t/firefox-removable-media-interface-auto-connect-request/5929