Local root vulnerability in snap-confine [LWN.net]

Local root vulnerability in snap-confine

Posted Feb 18, 2022 18:21 UTC (Fri) by jra (subscriber, #55261)
In reply to: Local root vulnerability in snap-confine by mfuzzey
Parent article: Local root vulnerability in snap-confine

One of the things I'd like to see is wide knowledge and availability of MNT_NOSYMFOLLOW use, and making it available as a normal mount flag.

Then applications can state:

"This application is only known to be secure when used on a filesystem mounted with the MNT_NOSYMFOLLOW option. Use on filesystems allowing symlinks can lead to race conditions and security vulnerabilities."

Let admins know how to protect themselves from this misfeature.

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Local root vulnerability in snap-confine

Posted Feb 19, 2022 6:23 UTC (Sat) by intelfx (subscriber, #130118) [Link] (1 responses)

> "This application is only known to be secure when used on a filesystem mounted with the MNT_NOSYMFOLLOW option. Use on filesystems allowing symlinks can lead to race conditions and security vulnerabilities."

I wouldn't use such software.

Local root vulnerability in snap-confine

Posted Feb 19, 2022 23:21 UTC (Sat) by jra (subscriber, #55261) [Link]

If I can get this mount flag to be easily used I will certainly add it to the recommended settings for a Samba server.

I'm sick of symlink insanity.