CVE-2021-41195: Crash in `tf.math.segment_*` operations

Impact

The implementation of tf.math.segment_* operations results in a CHECK-fail related abort (and denial of service) if a segment id in segment_ids is large.

import tensorflow as tf

tf.math.segment_max(data=np.ones((1,10,1)), segment_ids=[1676240524292489355])
tf.math.segment_min(data=np.ones((1,10,1)), segment_ids=[1676240524292489355])
tf.math.segment_mean(data=np.ones((1,10,1)), segment_ids=[1676240524292489355])    
tf.math.segment_sum(data=np.ones((1,10,1)), segment_ids=[1676240524292489355])
tf.math.segment_prod(data=np.ones((1,10,1)), segment_ids=[1676240524292489355])

This is similar to CVE-2021-29584 (and similar other reported vulnerabilities in TensorFlow, localized to specific APIs): the implementation (both on CPU and GPU) computes the output shape using AddDim. However, if the number of elements in the tensor overflows an int64_t value, AddDim results in a CHECK failure which provokes a std::abort. Instead, code should use AddDimWithStatus.

Patches

We have patched the issue in GitHub commit e9c81c1e1a9cd8dd31f4e83676cab61b60658429 (merging #51733).

The fix will be included in TensorFlow 2.7.0. We will also cherrypick this commit on TensorFlow 2.6.1, TensorFlow 2.5.2, and TensorFlow 2.4.4, as these are also affected and still in supported range.

For more information

Please consult our security guide for more information regarding the security model and how to contact us with issues and questions.

Attribution

This vulnerability has been reported externally via a GitHub issue.