Issue: ClientSidePhishingModel::IsEnabled() Returns False – Model Not Loaded or Invalid

[Shibani Das]

Hello everyone, 

I am currently investigating why ClientSideService::IsModelAvailable() returns false in my build (link: https://source.chromium.org/chromium/chromium/src/+/main:components/safe_browsing/content/browser/client_side_detection_host.cc;l=983;drc=99b6e0c14ba2ff4b37177af3a34c67f678af59d6). I traced down the issue and it originates from this function - 

bool ClientSidePhishingModel::IsEnabled() const {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  return (model_type_ == CSDModelType::kFlatbuffer &&
          mapped_region_.IsValid() && visual_tflite_model_ &&
          visual_tflite_model_->IsValid());
}

(link: https://source.chromium.org/chromium/chromium/src/+/main:components/safe_browsing/content/browser/client_side_phishing_model.cc;l=480;drc=d8339909e772f45502507714aed010c6ec2f605c;bpv=1;bpt=1).

In my case, each of the conditions above is false, like model_type != kFlatbuffer, mapped_region_.IsValid() is false, visual_tflite_model_ is not valid, ultimately leading to ClientSideService::IsModelAvailable() being false. I suspect the model is not being loaded at all. Can you point me to some references to resolve this issue or show me how to verify that the model has been loaded successfully or not? And if the model is not loaded what are the steps I should do? 

Any help is greatly appreciated.

Thank you so much for your attention and time. 

Sincerely,

Shibani Das.

[Shibani Das]

Hello, 

This is a follow up on the previous mail regarding why ClientSideService::IsModelAvailable() returning false in my build. 

Any help is greatly appreciated. 

Thank you so much.

Sincerely,

Shibani Das.

[Daniel Rubery]

Hello,

That does sound like a failure to load the model to me. You can confirm that by opening chrome://histograms#SBClientPhishing. The histogram SBClientPhishing.ModelDynamicUpdateSuccess records whether we successfully updated the model.

As far as further debugging, the phishing model should be initialized here. I'd recommend adding logging/breakpoints to that function so you can debug what's going wrong with model loading.

Thanks,

Dan Rubery

[Shibani Das]

Hello Daniel,

Thank you so much for your response. I followed your suggestion and checked the histograms at chrome://histograms#SBClientPhishing. I see entries such as:

SBClientPhishing.ModelDynamicUpdateSuccess → mean = 1.0 (all values at 1)
SBClientPhishing.PhishingDetectorResult → a sample recorded with value 0
Other metrics like PhishingDetectionDuration, ImageEmbedder.Event, etc.

I have attached screenshots of the histograms. I am not entirely sure how to interpret these results. For example, does ModelDynamicUpdateSuccess = 1.0 confirm that the phishing model is loading correctly? And what does the single PhishingDetectorResult = 0 sample signify in this context? 

Could you clarify more about this? This would help me confirm whether the model is working as expected or if additional debugging is still required.

We really appreciate you for your time and guidance.

Sincerely,

Shibani Das.

[zinov...@gmail.com]

These histograms descriptions can be found at https://source.chromium.org/chromium/chromium/src/+/main:tools/metrics/histograms/metadata/sb_client/histograms.xml;l=767?q=SBClientPhishing.ModelDynamicUpdateSuccess&ss=chromium

среда, 3 сентября 2025 г. в 21:43:27 UTC+3, Shibani Das:

[Shibani Das]

Thank you so much. 

[Desmond Ruhling]

You're welcome 🫶

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