[Android] GIF image loading causes file descriptor leak (FD count grows indefinitely) only when images are visible on screen

[m7yun]

Steps to reproduce

When loading and displaying GIF images on Android, the number of open file descriptors (FD) increases indefinitely and never gets released, eventually causing the app to become unresponsive or crash due to FD exhaustion.

Important finding: The FD leak only occurs when GIF images are actually visible on screen. When GIFs are scrolled off-screen or the widget is unmounted, the FD count does NOT increase. This suggests the leak is related to active decoding/rendering of GIF frames, not just caching or loading.

This issue started occurring in Flutter 3.41.x and persists in 3.44.0. The same code works perfectly in Flutter 3.38.10.

1.Create a simple Flutter app that loads GIF images (e.g., using Image.network or Image.asset)

2.Keep the GIFs visible on screen (e.g., in a ListView without scrolling, or a PageView)

3.Monitor FD count using /proc/self/fd

4.Observe FD count continuously increasing while GIFs are visible

5.Scroll the GIFs off-screen or navigate away — FD growth stops

Expected results

FD count should remain stable regardless of whether GIFs are visible on screen.

Actual results

GIFs visible on screen → FD count grows indefinitely

GIFs not visible (scrolled off-screen / disposed) → FD count remains stable

Eventually FD limit is reached (typically 1024-4096), causing app to slow down and crash

Code sample

Code sample

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('GIF FD Leak Test')),
        body: ListView.builder(
          itemCount: 20,
          itemBuilder: (context, index) => Image.network(
            'https://example.com/animated.gif', // Any GIF URL
            height: 300,
          ),
        ),
      ),
    );
  }
}

FD Monitoring Code (Kotlin)
Add this to MyApplication.kt:

Code sample

Handler(Looper.getMainLooper()).post(object : Runnable {
    override fun run() {
        val fdCount = File("/proc/self/fd").listFiles()?.size ?: 0
        Log.d("FD_Monitor", "Current FD count: $fdCount")
        Handler(Looper.getMainLooper()).postDelayed(this, 2000)
    }
})

Screenshots or Video

Screenshots / Video demonstration

[Upload media here]

Logs

// With GIFs VISIBLE on screen:

Logs

D/FD_Monitor: Current FD count: 247
D/FD_Monitor: Current FD count: 312
D/FD_Monitor: Current FD count: 389
D/FD_Monitor: Current FD count: 451
D/FD_Monitor: Current FD count: 523
D/FD_Monitor: Current FD count: 598
... (continues growing until crash)

// After scrolling GIFs OFF screen:

Logs

D/FD_Monitor: Current FD count: 598
D/FD_Monitor: Current FD count: 599
D/FD_Monitor: Current FD count: 598
D/FD_Monitor: Current FD count: 597
... (stable, no further growth)

Flutter Doctor output

Doctor output

[✓] Flutter (Channel stable, 3.41.6)
[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
[✓] Xcode (Version 15.4)
[✓] VS Code (version 1.89.1)
[✓] Connected device (1 available)

[m7yun]

Additional Context
Platform: Android only (iOS works fine)

Android versions tested: 12, 13, 14

Devices tested: Pixel, Xiaomi, Samsung

Image format: GIF only (PNG, JPEG, WebP work fine)

Leak condition: Only when GIF is actively being rendered on screen

Not a caching issue: cached_network_image_ce does not solve it

Possible Root Cause
Based on the "visible only" behavior, the leak likely occurs in the on-screen rendering pipeline for animated GIFs, specifically:

The frame decoder may be opening file descriptors per frame/animation cycle

These FDs are not being closed when frames are rendered

The issue was likely introduced by changes to ImageDecoder or SkCodec between Flutter 3.38.10 and 3.41.0

Request
Please investigate the GIF decoding and frame rendering implementation in the Android engine layer, with special attention to:

File descriptor lifecycle during active GIF animation

Differences in lib/ui/painting/image_decoder.cc between versions 3.38.10 and 3.41.0

Whether SkCodec or ImageDecoder is properly closing resources after each frame

Thank you!

[mbcorona]

Thanks for the report. I tried to reproduce this on Flutter 3.44.0 (the version you say still affects this) on a physical Android device, using a real GIF in the same ListView setup you described. I monitored the FD count via run-as for over 20 minutes with the GIFs visible.
The FD count stayed stable between 150 and 202 the whole time — no growth, no approach to any limit. It actually went down over time as the initial network sockets closed.
A few things that would help us investigate further:
Could you share a runnable repro with a real GIF URL (not the example.com placeholder), ideally as a GitHub repo or gist?
Your flutter doctor shows 3.41.6 but the report mentions 3.44.0 — did you actually test on 3.44.0? It didn't reproduce there for me.
Could you also share full flutter doctor -v output, the device model, and whether your real app uses plugins that might open FDs on their own (networking, video, audio, camera, etc.)? Your starting FD count of 247 is already higher than what I see on a baseline Flutter app, so something in your setup may be contributing.

[m7yun]

Thanks for the report. I tried to reproduce this on Flutter 3.44.0 (the version you say still affects this) on a physical Android device, using a real GIF in the same ListView setup you described. I monitored the FD count via run-as for over 20 minutes with the GIFs visible. The FD count stayed stable between 150 and 202 the whole time — no growth, no approach to any limit. It actually went down over time as the initial network sockets closed. A few things that would help us investigate further: Could you share a runnable repro with a real GIF URL (not the example.com placeholder), ideally as a GitHub repo or gist? Your flutter doctor shows 3.41.6 but the report mentions 3.44.0 — did you actually test on 3.44.0? It didn't reproduce there for me. Could you also share full flutter doctor -v output, the device model, and whether your real app uses plugins that might open FDs on their own (networking, video, audio, camera, etc.)? Your starting FD count of 247 is already higher than what I see on a baseline Flutter app, so something in your setup may be contributing.

Hello,

After my testing, I found that this FD leak issue occurs when loading GIF images inside a ListView component. It happens with both the standard ListView and ListView.builder.

Key observations:

The FD count only increases when GIF images are visible on screen

When I scroll up until all GIF images move off the visible area, the FD count stabilizes and stops growing

Please note that my project only loads GIFs inside ListView. I have not tested other scrolling components such as GridView or SingleChildScrollView.

You can reproduce this issue using the following sample code:

Code sample

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(colorScheme: .fromSeed(seedColor: Colors.deepPurple)),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  List<String> list = [
    'http://img-haodanku-com.cdn.fudaiapp.com/452ab4d5b7c95afba96735254fc9edb4.gif',
    'http://img.haodanku.com/d5e078f8c6e71841736f1df1c9cb12d2.gif',
    'http://img-haodanku-com.cdn.fudaiapp.com/5a859b97c53f631a1c50590defdc253c.gif',
    'http://video.haodanku.com/304f8426ac09c1bf7e2ee0d52df4dce0.gif',
    'http://img-haodanku-com.cdn.fudaiapp.com/954664d170dfed91cb4f0b9abf93eef8.gif',
    'http://img-haodanku-com.cdn.fudaiapp.com/717a79dbc29c2dd771facb47aef0c3ed.gif',
    'http://img.haodanku.com/61a08a81783bd253f6f59fc096e7fe3a.gif',
    'http://img-haodanku-com.cdn.fudaiapp.com/35eeadc246f3333de65398c0e5ea2164.gif',
    'https://img.alicdn.com/bao/uploaded/O1CN01Xusw6y1T7TlxRXDiQ_!!6000000002335-0-yinhe.jpg',
    'https://img.alicdn.com/bao/uploaded/O1CN01Xusw6y1T7TlxRXDiQ_!!6000000002335-0-yinhe.jpg',
    'https://img.alicdn.com/bao/uploaded/O1CN01Xusw6y1T7TlxRXDiQ_!!6000000002335-0-yinhe.jpg',
    'https://img.alicdn.com/bao/uploaded/O1CN01Xusw6y1T7TlxRXDiQ_!!6000000002335-0-yinhe.jpg',
    'https://img.alicdn.com/bao/uploaded/O1CN01Xusw6y1T7TlxRXDiQ_!!6000000002335-0-yinhe.jpg',
    'https://img.alicdn.com/bao/uploaded/O1CN01Xusw6y1T7TlxRXDiQ_!!6000000002335-0-yinhe.jpg',
    'https://img.alicdn.com/bao/uploaded/O1CN01Xusw6y1T7TlxRXDiQ_!!6000000002335-0-yinhe.jpg',
    'https://img.alicdn.com/bao/uploaded/O1CN01Xusw6y1T7TlxRXDiQ_!!6000000002335-0-yinhe.jpg',
    'https://img.alicdn.com/bao/uploaded/O1CN01Xusw6y1T7TlxRXDiQ_!!6000000002335-0-yinhe.jpg',
    'https://img.alicdn.com/bao/uploaded/O1CN01Xusw6y1T7TlxRXDiQ_!!6000000002335-0-yinhe.jpg',
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: ListView(
        children: list
            .map(
              (e) => Container(
                alignment: Alignment.center,
                child: Image.network(e, width: 100, height: 200),
              ),
            )
            .toList(),
      ),
    );
  }
}

Log Output

With GIFs VISIBLE on screen

2026-05-23 02:28:25.665  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 131
2026-05-23 02:28:27.668  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 190
2026-05-23 02:28:29.672  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 206
2026-05-23 02:28:31.675  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 224
2026-05-23 02:28:33.696  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 241
2026-05-23 02:28:35.700  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 259
2026-05-23 02:28:37.704  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 276
2026-05-23 02:28:39.715  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 292
2026-05-23 02:28:41.725  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 304
2026-05-23 02:28:43.738  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 322
2026-05-23 02:28:45.747  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 340
2026-05-23 02:28:47.756  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 357
2026-05-23 02:28:49.766  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 373
2026-05-23 02:28:51.775  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 390
2026-05-23 02:28:53.782  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 407
2026-05-23 02:28:55.793  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 424
2026-05-23 02:28:57.800  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 442
2026-05-23 02:28:59.810  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 459
2026-05-23 02:29:01.818  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 477
2026-05-23 02:29:03.836  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 493
2026-05-23 02:29:05.849  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 509
2026-05-23 02:29:07.861  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 535

After scrolling GIFs OFF screen

2026-05-23 02:29:09.904  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 535
2026-05-23 02:29:11.929  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 535
2026-05-23 02:29:13.953  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 535
2026-05-23 02:29:15.973  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 535
2026-05-23 02:29:17.997  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 535
2026-05-23 02:29:20.019  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 535
2026-05-23 02:29:22.079  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 535
2026-05-23 02:29:24.128  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 532
2026-05-23 02:29:26.153  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 532
2026-05-23 02:29:28.176  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 532
2026-05-23 02:29:30.196  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 532
2026-05-23 02:29:32.219  8865-8865  FD_Monitor              com.example.test                     D  Current FD count: 532

Flutter Doctor output

Doctor output

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.44.0, on macOS 15.7.4 24G517 darwin-x64, locale
    zh-Hans-CN)
[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 26.2)
[✓] Chrome - develop for the web
[✓] Connected device (4 available)
[✓] Network resources

• No issues found!

[jason-simmons]

Reproduced this using the app from #186899 (comment) and the Impeller/GLES back end.

The app is displaying an animated WebP image that loops infinitely, so the engine is continuously creating TextureGLES instances. The file descriptor leak happens because some of those textures are leaking their GL fence sync objects.

Normally if a fence has been set on a TextureGLES, then it will be deleted when TextureGLES::Bind is called. But when the animated image creates frames nonstop, some of the resulting textures never get a Bind call. The TextureGLES destructor then does not clean up the fence.

[m7yun]

Reproduced this using the app from #186899 (comment) and the Impeller/GLES back end.

The app is displaying an animated WebP image that loops infinitely, so the engine is continuously creating TextureGLES instances. The file descriptor leak happens because some of those textures are leaking their GL fence sync objects.

Normally if a fence has been set on a TextureGLES, then it will be deleted when TextureGLES::Bind is called. But when the animated image creates frames nonstop, some of the resulting textures never get a Bind call. The TextureGLES destructor then does not clean up the fence.

Thank you for your attention and detailed response.

I have verified that this issue only reproduces when Impeller is enabled. Running the app with flutter run --no-enable-impeller works fine without any FD leak.

May I ask what the estimated timeline is for a fix and an upcoming stable release?

Best regards.