Closed Bug 535097 Opened 15 years ago Closed 8 years ago

Infinite loop in javascript freezes firefox

Categories

(Core :: JavaScript Engine, defect)

Product:
Core
Component:
JavaScript Engine
Type:
defect
Priority:
Not set
Severity:
critical

Tracking

()

Status:
RESOLVED DUPLICATE of bug 516752

People

(Reporter: mangatmodi, Unassigned)

References

Details

(Keywords: hang)

Attachments

(4 files)

reporter's testcase
378 bytes, text/html
Details
This is the new test case, without Document.write
357 bytes, text/html
Details
A variation of bug 535097
871 bytes, text/html
Details
JS_loop_hang_and_crash_regression_Firefox_Aurora_2013-08-23.txt
4.62 KB, text/plain
Details 
User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2b4) Gecko/20091124 Ant.com Toolbar 1.5 Firefox/3.6b4
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2b4) Gecko/20091124 Ant.com Toolbar 1.5 Firefox/3.6b4

I accidentally created an HTML file with an Infinite loop in javascript. When I opened this file in firefox, it freezes. Firefox became non responsive and consumed 800Mb+ main memory and 50%+ CPU.

This bug is a very easy to think and I was surprised that it is still not patched !!

Reproducible: Always

Steps to Reproduce:
1. Save the html code given in addition content as an html file.
2. Open the file with firefox

Actual Results:  
1. Firefox became non-responsive
2. Increased memory and cpu utilization

Expected Results:  
Firefox should give some Unresponsive script alert Instead of loading that page.

<!-------SCRIPT TO TEST----------------->
<html>
<body>

<script type="text/javascript">
for (i = 0; i <= 5; )
{
document.write("The number is " + i);
document.write("<br />");
}
</script>

<p>Explanation:</p>

<p>This for loop starts with i=0.</p>

<p>As long as <b>i</b> is less than, or equal to 5, the loop will continue to run.</p>

<p>But, <b>i</b>here never increments !!</p>

</body>
</html>
Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.3a1pre) Gecko/20091215 Minefield/3.7a1pre

Confirmed that it hangs. I see this also with older Firefox versions.
Assignee: nobody → general
Component: General → JavaScript Engine
Product: Firefox → Core
QA Contact: general → general
Version: unspecified → Trunk
yes,
Infinite looping is prevented in Internet Explorer. Try opening this file in Internet Explorer.

I think it's a major slip in firefox
I suspect that the problem here lies in the DOM code's control of the script timer, because of the required parser interaction.  (If I remove the document.write calls I get the dialog as expected.)
Assignee: general → nobody
Status: UNCONFIRMED → NEW
Component: JavaScript Engine → DOM
Ever confirmed: true
QA Contact: general → general
This is the new test case without Document object. But the page is still freezing !!
It hangs indeed with a big hourglass and an unresponsive browser.
Keywords: hang
(In reply to comment #5)
> Created an attachment (id=417921) [details]
> This is the new test case, without Document.write
> 
> This is the new test case without Document object. But the page is still
> freezing !!

This one gives me an unresponsive script dialog just fine in 3.5, as comment #4 indicated.

    
    

    
  
Comment on attachment 428067 [details]
A variation of bug 535097

I've had a discovery similar to this bug. My code spawns infinite alertboxes.

Windows stop responding.
I had to ctrl+alt+del -> taskman -> kill firefox.exe

Mem usage: 740k+
Cpu usage: 50%

    
    

    
  
Only the second testcase gave me trouble on Firefox 4.0b7 (32 bit Windows 7), but pressing escape closed the script dialog (the stop button didn't work).

    
    

    
  
Still freezes Firefox 20.x
Come on, guys, this is really common due to JSON Hijacking security work-arounds.  Lots of apps set the start of a JSON response page to  for(;;)  
If you accidentally pull that down outside of the right client code, your entire Firefox process is frozen forever, and you have to kill off all of Firefox.

This is really embarrassing to still be in the product.

    
    

    
  
want to debug this , only thing i am new to mozilla development.Since i do not have much of an idea how do i go about this.Thanks in advance.
Assignee: nobody → general
Component: DOM → JavaScript Engine
OS: Windows XP → All
Hardware: x86 → All

    
    

    
  
IMHO, the core problem is that, slow JavaScript programs freeze not only the page, but also the whole Firefox browser, which is unacceptable.

    
    

    
  
The first testcase of bug 535097 hangs and crashes Aurora 25.0a2 (2013-08-23) on 64-bit Windows 7. firefox.exe stack from Process Explorer:

ntoskrnl.exe!KeWaitForMultipleObjects+0xc0a
ntdll.dll!RtlLeaveCriticalSection+0x26
MSVCR100.dll!wcspbrk+0x77
mozglue.dll!free+0x6be
mozglue.dll!realloc+0x33
xul.dll!NS_RegisterMemoryReporter+0x16c37
xul.dll!JSD_IsLockingAndThreadIdSupported+0x30a70
xul.dll!NS_RegisterMemoryReporter+0x16ff9
xul.dll!NS_CycleCollectorSuspect3+0x1fdcc

Toepassing: Firefox 25.0a2 (20130823004003)
Besturingssysteem: WINNT (x86-msvc)

- Add-on Compatibility Reporter 2.0.1
- BarTab 2.0 (Uitgeschakeld, Niet compatibel)
- British English Dictionary 1.19.1 (Uitgeschakeld)
- CacheViewer 0.6.3 (Uitgeschakeld, Niet compatibel)
- Compact Menu 2 4.3.1
- Copy Title 1.1 (Uitgeschakeld)
- Custom Tab Width 1.0.1
- Download Sort 2.5.8 (Uitgeschakeld)
- DownloadHelper 4.9.17
- Extension List Dumper 1.15.2
- File Title 1.4 (Uitgeschakeld)
- Firebug 1.12.0 (Uitgeschakeld)
- Flash and Video Download 1.37 (Uitgeschakeld)
- Flashblock 1.5.17
- foxiFrame basic 5.1 (Uitgeschakeld, Niet compatibel)
- FoxyProxy Standard 4.2.1 (Uitgeschakeld)
- Free Download Manager plugin 1.5.7.6 (Uitgeschakeld, Niet compatibel)
- Full Fullscreen 3.4 (Uitgeschakeld, Niet compatibel)
- Gecko Profiler 1.10.17 (Uitgeschakeld, Niet compatibel)
- InvisibleHand 3.8.28 (Uitgeschakeld)
- Live HTTP headers 0.17 (Uitgeschakeld)
- Mozilla Archive Format 2.0.9
- New Tab JumpStart 0.5a5.5.3 (Uitgeschakeld)
- Nightly Tester Tools 3.6 (Uitgeschakeld)
- RealDownloader 1.2.0 (Uitgeschakeld)
- Secure Login 1.0.3
- Session Manager 0.8.0.8
- Show the Image 0.7 (Uitgeschakeld)
- Showcase 0.9.5.10 (Uitgeschakeld)
- Silvermel and Charamel XT 1.5.5 (Uitgeschakeld)
- Tab Kit 0.6 (Uitgeschakeld, Niet compatibel)
- Test Pilot 1.2.2 (Uitgeschakeld)
xul.dll!NS_CycleCollectorSuspect3+0x100f7

    
    

    
  


  
This is after restarting in safe mode (disabled addons). Bug 905131 might be related.
Assignee: general → nobody

    
    

    
  
The second testcase shows a slow script dialog as expected and loads fine when you stop the script. The initial document.write test also works fine, albeit slowly, printing "The number is 0" to the page until you close the browser. Note that this was tested in nightly with e10s enabled. It might still iloop and block interaction in release channels, but that's not a regression. Given that this is totally fixed by e10s, I'm going to dup it to that bug.
Status: NEW → RESOLVED
Closed: 8 years ago
Resolution: --- → DUPLICATE

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