1719279 - $HOME/.cache/fontconfig should be rdonly but is not added

Status: RESOLVED FIXED

(Core :: Security: Process Sandboxing, defect, P1)

Description

[:gerard-majax]

While working on bug 1718084, tracing calls to policy->AddDir() shows that while we should be authorizing access to $HOME/.cache/fontconfig as per https://searchfox.org/mozilla-central/rev/5b3444ad300e244b5af4214212e22bd9e4b7088a/security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp#397 we actually dont:

 0:03.70 GECKO(3645994) [Parent 3645994, Main Thread] WARNING: Trying to add extraConfDirsAllow: file /home/alexandre/Documents/codaz/Mozilla/MiscWork/mozilla-source/mozilla-unified/security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp:415
 0:03.70 GECKO(3645994) policy->AddDir(rdonly, /home/alexandre/.config)
 0:03.70 GECKO(3645994) [Parent 3645994, Main Thread] WARNING: Trying to add extraConfDirsAllow: file /home/alexandre/Documents/codaz/Mozilla/MiscWork/mozilla-source/mozilla-unified/security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp:415
 0:03.70 GECKO(3645994) policy->AddDir(rdonly, /home/alexandre/.themes)
 0:03.70 GECKO(3645994) [Parent 3645994, Main Thread] WARNING: Trying to add extraConfDirsAllow: file /home/alexandre/Documents/codaz/Mozilla/MiscWork/mozilla-source/mozilla-unified/security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp:415
 0:03.70 GECKO(3645994) policy->AddDir(rdonly, /home/alexandre/.fonts)
 0:03.70 GECKO(3645994) [Parent 3645994, Main Thread] WARNING: Trying to add extraConfDirsAllow: file /home/alexandre/Documents/codaz/Mozilla/MiscWork/mozilla-source/mozilla-unified/security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp:415
 0:03.70 GECKO(3645994) [Parent 3645994, Main Thread] WARNING: Trying to add extraConfDirsBlock: file /home/alexandre/Documents/codaz/Mozilla/MiscWork/mozilla-source/mozilla-unified/security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp:431

I guess https://searchfox.org/mozilla-central/rev/5b3444ad300e244b5af4214212e22bd9e4b7088a/security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp#409-410 does not like that we pass .cache/fontconfig as a path component

Comment 1

[:gerard-majax]

https://searchfox.org/mozilla-central/rev/5b3444ad300e244b5af4214212e22bd9e4b7088a/xpcom/io/nsLocalFileUnix.cpp#560-565

Comment 2

[:gerard-majax]

Attachment: Bug 1719279 - Properly add $HOME/.cache/fontconfig allowance r?gcp

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c48601422906
Properly add $HOME/.cache/fontconfig allowance r=gcp

Comment 4

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/c48601422906

Comment 5

[Ryan VanderMeulen [:RyanVM]]

Please nominate this for ESR91 approval (it'll simplify the uplift of bug 1718084).

Comment 6

[:gerard-majax]

Comment on attachment 9229865 [details]
Bug 1719279 - Properly add $HOME/.cache/fontconfig allowance r?gcp

ESR Uplift Approval Request

• If this is not a sec:{high,crit} bug, please state case for ESR consideration: easier to uplift bug 1732580
• User impact if declined: no webgl on snap package
• Fix Landed on Version: 92
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): tested, landed for three months, no known regression
• String or UUID changes made by this patch:

Comment 7

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9229865 [details]
Bug 1719279 - Properly add $HOME/.cache/fontconfig allowance r?gcp

Approved for 91.3esr, thanks.

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-esr91/rev/f55f38244915