iOS crash in WebP decode path (SDImageWebPCoder/libwebp) on 8.13.0

[garshythoel]

Summary

Seeing a reproducible iOS crash in the WebP decode path when using FastImage with many dynamic WebP images on a screen (avatar grid/list use case).

Crash appears in SDImageWebPCoder -> libwebp decode and goes away if we avoid the SDImageWebPCoder path on iOS 14+.

Environment

• @d11/react-native-fast-image: 8.13.0
• React Native: 0.77.3
• Expo: 52.0.48
• iOS target app uses CocoaPods with:
  • RNFastImage (8.13.0)
  • SDWebImage (5.21.6)
  • SDWebImageWebPCoder (0.15.0)
  • libwebp (1.5.0)

Repro pattern

1. Render a screen with many remote WebP images via FastImage (in our case, avatar tab/grid).
2. Open that screen and scroll/trigger multiple image loads.
3. App crashes with EXC_BAD_ACCESS in WebP decode.

For context: the same image set did not crash in our pre-upgrade app version; issue appeared after upgrade.

Crash stack (excerpt)

• ExtractPalettedAlphaRows
• VP8LDecodeAlphaImageStream
• WebPDecode
• -[SDImageWebPCoder sd_createWebpImageWithData:colorSpace:scaledSize:]
• -[SDImageWebPCoder decodedImageWithData:options:]
• -[SDImageCodersManager decodedImageWithData:options:]
• SDImageCacheDecodeImageData
• -[SDImageCache diskImageForKey:data:options:context:]
• -[FFFastImageView downloadImage:options:context:]
• -[FFFastImageView reloadImage]

Queue shown at crash: com.hackemist.SDImageCache.ioQueue.

Workaround that fixed it for us

In FFFastImageView.mm coder registration (commonInitUtils), on iOS 14+:

• add SDImageAWebPCoder (Apple ImageIO WebP coder)
• remove SDImageWebPCoder

Pseudo-diff:

SDImageCodersManager *codersManager = [SDImageCodersManager sharedManager];
[codersManager addCoder:[SDImageAVIFCoder sharedCoder]];

if (@available(iOS 14.0, tvOS 14.0, *)) {
  Class aWebPCoderClass = NSClassFromString(@"SDImageAWebPCoder");
  if (aWebPCoderClass && [aWebPCoderClass respondsToSelector:@selector(sharedCoder)]) {
    id aWebPCoder = [aWebPCoderClass performSelector:@selector(sharedCoder)];
    if (aWebPCoder != nil) {
      [codersManager addCoder:aWebPCoder];
    }
  }
  [codersManager removeCoder:[SDImageWebPCoder sharedCoder]];
  return;
}

[codersManager addCoder:[SDImageWebPCoder sharedCoder]];

With this change, crash stopped in our testing.

Question

Would you consider an upstream option/guard for iOS 14+ to prefer AWebP over SDImageWebPCoder (or make WebP coder selection configurable), so apps can avoid this libwebp crash path without maintaining a local patch?

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