1680166 - Sandbox crashes when building with rustc >= 1.48

Status: RESOLVED FIXED

(Core :: Security: Process Sandboxing, task)

Description

[Emilio Cobos Álvarez (:emilio)]

Visiting pages that require opening files from rust like https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-color-scheme crashes if you have a local build with rust >= 1.48

Patch incoming.

Comment 1

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1680166 - Return EFAULT when given a null path to stat* calls in the sandbox filter. r=jld,gcp

It's a common way to check the existence of the system call. Since we
handle them, let's return -EFAULT as if it was supported.

This is needed for the sandbox not to constantly crash due to this statx
call in rustc:

https://github.com/rust-lang/rust/blob/09c9c9f7da72b774cc445c0f56fc0b9792a49647/library/std/src/sys/unix/fs.rs#L119-L123

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/60066199c32b
Return EFAULT when given a null path to stat* calls in the sandbox filter. r=gcp

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d69e924f3538
GCC is smarter than clang, so ignore the warning properly.

Comment 4

[Jed Davis [:jld] ⟨⏰|UTC-7⟩ ⟦he/him⟧]

Incidentally, that type of nullptr trick is also used by the sandbox to detect seccomp-bpf support / features.

Comment 5

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/60066199c32b
https://hg.mozilla.org/mozilla-central/rev/d69e924f3538

Comment 6

[Thomas Deutschmann]

Can we please get this uplifted into Firefox ESR 78? We are hitting this in Gentoo Linux with latest >=rust-1.50.

Comment 7

[Emilio Cobos Álvarez (:emilio)]

Comment on attachment 9190710 [details]
Bug 1680166 - Return EFAULT when given a null path to stat* calls in the sandbox filter. r=jld,gcp

ESR Uplift Approval Request

• If this is not a sec:{high,crit} bug, please state case for ESR consideration: Linux sandbox fix for newer compilers. See comment 6.
• User impact if declined: none
• Fix Landed on Version: 85
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Relatively straight-forward sandbox fix+test.
• String or UUID changes made by this patch: none

Comment 8

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9190710 [details]
Bug 1680166 - Return EFAULT when given a null path to stat* calls in the sandbox filter. r=jld,gcp

Approved for 78.11esr.

Comment 9

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-esr78/rev/ff436849850a
https://hg.mozilla.org/releases/mozilla-esr78/rev/8aa3952dd720