1500906 - Crash in android.os.FileUriExposedException: at android.os.StrictMode.onFileUriExposed(StrictMode.java)

Status: VERIFIED FIXED

(Firefox for Android Graveyard :: General, defect)

Description

[Gabriele Svelto [:gsvelto]]

This bug was filed from the Socorro interface and is
report bp-1215d19c-321c-49ae-91a8-da30c0181021.
=============================================================

Java stack trace:

android.os.FileUriExposedException
	at android.os.StrictMode.onFileUriExposed(StrictMode.java:1796)
	at android.net.Uri.checkFileUriExposed(Uri.java:2354)
	at android.content.Intent.prepareToLeaveProcess(Intent.java:9026)
	at android.content.Intent.prepareToLeaveProcess(Intent.java:8987)
	at android.app.Instrumentation.execStartActivity(Instrumentation.java:1519)
	at android.app.Activity.startActivityForResult(Activity.java:4321)
	at android.support.v4.app.BaseFragmentActivityApi16.startActivityForResult(BaseFragmentActivityApi16.java:54)
	at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:67)
	at android.app.Activity.startActivityForResult(Activity.java:4279)
	at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:720)
	at android.app.Activity.startActivity(Activity.java:4618)
	at android.app.Activity.startActivity(Activity.java:4586)
	at org.mozilla.gecko.ActivityHandlerHelper.startIntentAndCatch(ActivityHandlerHelper.java:33)
	at org.mozilla.gecko.IntentHelper.openUriExternal(IntentHelper.java:148)
	at org.mozilla.gecko.IntentHelper.open(IntentHelper.java:439)
	at org.mozilla.gecko.IntentHelper.handleMessage(IntentHelper.java:422)
	at org.mozilla.gecko.EventDispatcher$3.run(EventDispatcher.java:356)
	at android.os.Handler.handleCallback(Handler.java:751)
	at android.os.Handler.dispatchMessage(Handler.java:95)
	at android.os.Looper.loop(Looper.java:154)
	at android.app.ActivityThread.main(ActivityThread.java:6351)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:896)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:786)

Looking at the exception message it seems that we're trying to create an Intent with a file:// URI which is not supported anymore starting with API 24. It seems that to get around this either we have to use a less restrictive VM policy or we have to only use Intents with content:// URIs.

Comment 1

[Jan Henning [:JanH]]

Right, I guess this might be possibly users browsing the local file system (or having opened some file type we support in Firefox from some other app) and then attempting to open that document/image/... in some other app using our helper app system.

(In reply to Gabriele Svelto [:gsvelto] from comment #0)
> It seems that to get around this either we have to use a less
> restrictive VM policy or we have to only use Intents with content:// URIs.

We do the former, because for world-accessible files in the public storage content:// URIs aren't as great as Googles makes them out to be (just look at what we have to do in order to properly display an HTML file we receive via a content:// URI). I handled downloads, and know that normal sharing doesn't work for file:// URIs, but didn't think of the helper app system.

Comment 2

[Jan Henning [:JanH]]

Attachment: Bug 1500906 - Suppress FileUriExposedExceptions when launching helper apps. r?esawin

Sharing tabs with file:// URIs is not possible, but users can still send them to
other apps via the helper app system in the URL bar/context menu. "Intent:Open"
and "Intent:OpenForResult" are both sent from Gecko by HelperApps.jsm.

The same reasoning as in bug 1450449 applies as to why for publicly accessible
files content:// URIs are more trouble than they're worth.

Comment 3

[Jan Henning [:JanH]]

I guess this could count as a regression caused by the target API26 migration.

Comment 4

[Pascal Chevrel:pascalc (PTO until April 26)]

Tracking for a potential 63 dot release.

Comment 5

[Jan Henning [:JanH]]

Attachment: Bug 1500906 - Suppress FileUriExposedExceptions when launching helper apps. r?esawin

Sharing tabs with file:// URIs is not possible, but users can still send them to
other apps via the helper app system in the URL bar/context menu. "Intent:Open"
and "Intent:OpenForResult" are both sent from Gecko by HelperApps.jsm.

The same reasoning as in bug 1450449 applies as to why for publicly accessible
files content:// URIs are more trouble than they're worth.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/73cfb79f183a
Suppress FileUriExposedExceptions when launching helper apps. r=jchen

Comment 7

[Jan Henning [:JanH]]

Comment on attachment 9019105 [details]
Bug 1500906 - Suppress FileUriExposedExceptions when launching helper apps. r?esawin

[Beta/Release Uplift Approval Request]

Feature/Bug causing the regression: Bug 1485151

User impact if declined: Firefox will crash on Android N and later if viewing a locally stored file and attempting to use our helper app system (context menu link or the Android icon in the URL bar) to launch that file in an external app.

Is this code covered by automated tests?: No

Has the fix been verified in Nightly?: No

Needs manual test from QE?: Yes

If yes, steps to reproduce: Open a local file in Firefox (so you get a file://-URI in the URLbar) that can also be opened in some other locally installed app - some media file is most likely to work. Using the Android icon in the URLbar to launch the current page in Firefox in an external app using a file:// URI should no longer trigger a crash.

List of other uplifts needed: None

Risk to taking this patch: Low

Why is the change risky/not risky? (and alternatives if risky): Trivial change to temporarily disable the corresponding strict mode checks when launching helper apps - we also do the same thing for downloads already.

String changes made/needed: none

Comment 8

[Jan Henning [:JanH]]

Comment on attachment 9019807 [details]
Bug 1500906 - Suppress FileUriExposedExceptions when launching helper apps. r?esawin

[Beta/Release Uplift Approval Request]

Feature/Bug causing the regression: Bug 1473872

User impact if declined: Firefox will crash on Android N and later if viewing a locally stored file and attempting to use our helper app system (context menu link or the Android icon in the URL bar) to launch that file in an external app.

Is this code covered by automated tests?: No

Has the fix been verified in Nightly?: No

Needs manual test from QE?: Yes

If yes, steps to reproduce: Open a local file in Firefox (so you get a file://-URI in the URL bar) that can also be opened in some other locally installed app - some media file is most likely to work. Using the Android icon in the URL bar to launch the current page in Firefox in an external app using a file:// URI should no longer trigger a crash.

List of other uplifts needed: None

Risk to taking this patch: Low

Why is the change risky/not risky? (and alternatives if risky): Trivial change to temporarily disable the corresponding strict mode checks when launching helper apps - we also do the same thing for downloads already.

String changes made/needed: none

Comment 9

[Jan Henning [:JanH]]

Comment on attachment 9019807 [details]
Bug 1500906 - Suppress FileUriExposedExceptions when launching helper apps. r?esawin

[Beta/Release Uplift Approval Request]

Feature/Bug causing the regression: None

User impact if declined: 

Is this code covered by automated tests?: Yes

Has the fix been verified in Nightly?: Yes

Needs manual test from QE?: Yes

If yes, steps to reproduce: 

List of other uplifts needed: None

Risk to taking this patch: Low

Why is the change risky/not risky? (and alternatives if risky): 

String changes made/needed:

Comment 10

[Jan Henning [:JanH]]

Release requires a separate patch because bug 1485151, which allows a more concise way of temporarily disabling strict mode, is only in Firefox 64.

Comment 11

[Raul Gurzau (:RaulG)]

https://hg.mozilla.org/mozilla-central/rev/73cfb79f183a

Comment 12

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9019105 [details]
Bug 1500906 - Suppress FileUriExposedExceptions when launching helper apps. r?esawin

Fixes a Fennec crash. Approved for 64.0b4 (or b5, I haven't decided yet if I'm going to spin a Fennec b4 or not yet).

Comment 13

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/2cbb3d6f52b0

Comment 14

[Sorina Florean [:sflorean]]

Verified as fixed on Nightly build 65.0a1 and 64.0b4 with the following devices: Huawei Honor 8(Android 7.0) and Samsung Galaxy Note 8(Android 8.0.0).

Comment 15

[Pascal Chevrel:pascalc (PTO until April 26)]

Comment on attachment 9019807 [details]
Bug 1500906 - Suppress FileUriExposedExceptions when launching helper apps. r?esawin

Patch already on Nightly 65 and uplifted to 64 with no regression reported. The last 2 betas with this patch have seen crashes reduced very significantly for this signature. Uplift approved to release for our next dot release for 63. Thanks.

Comment 16

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-release/rev/b71bed0c6a40

Comment 17

[Sorina Florean [:sflorean]]

Verified as fixed on RC build 63.0.2 following the steps from comment 8.
Devices: Nokia 6(Android 7.1.1) and Samsung Galaxy Tab S3(Android 8.0).