Division by 0 in `QuantizedMul`

### Impact An attacker can trigger a division by 0 in `tf.raw_ops.QuantizedMul`: ```python import tensorflow as tf x = tf.zeros([4, 1], dtype=tf.quint8) y = tf.constant([], dtype=tf.quint8) min_x = tf.constant(0.0) max_x = tf.constant(0.0010000000474974513) min_y = tf.constant(0.0) max_y = tf.constant(0.0010000000474974513) tf.raw_ops.QuantizedMul(x=x, y=y, min_x=min_x, max_x=max_x, min_y=min_y, max_y=max_y) ``` This is because the [implementation](https://github.com/tensorflow/tensorflow/blob/55900e961ed4a23b438392024912154a2c2f5e85/tensorflow/core/kernels/quantized_mul_op.cc#L188-L198) does a division by a quantity that is controlled by the caller: ```cc template <class T, class Toutput> void VectorTensorMultiply(const T* vector_data, int32 vector_offset, int64 vector_num_elements, const T* tensor_data, int32 tensor_offset, int64 tensor_num_elements, Toutput* output) { for (int i = 0; i < tensor_num_elements; ++i) { const int64 vector_i = i % vector_num_elements; ... } } ``` ### Patches We have patched the issue in GitHub commit [a1b11d2fdd1e51bfe18bb1ede804f60abfa92da6](https://github.com/tensorflow/tensorflow/commit/a1b11d2fdd1e51bfe18bb1ede804f60abfa92da6). The fix will be included in TensorFlow 2.5.0. We will also cherrypick this commit on TensorFlow 2.4.2, TensorFlow 2.3.3, TensorFlow 2.2.3 and TensorFlow 2.1.4, as these are also affected and still in supported range. ### For more information Please consult [our security guide](https://github.com/tensorflow/tensorflow/blob/master/SECURITY.md) for more information regarding the security model and how to contact us with issues and questions. ### Attribution This vulnerability has been reported by Ying Wang and Yakun Zhang of Baidu X-Team.

CVSS 3.1

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L

Severity from

GitHub (reviewed advisory)

Weakness

CWE-369

Also known as

BIT-tensorflow-2021-29528, CVE-2021-29528, PYSEC-2021-165, PYSEC-2021-456, PYSEC-2021-654

• github.com/tensorflow/tensorflow/security/advisories/GHSA-6f84-42vf-ppwp
• nvd.nist.gov/vuln/detail/CVE-2021-29528
• github.com/tensorflow/tensorflow/commit/a1b11d2fdd1e51bfe18bb1ede804f60abfa92da6
• github.com/pypa/advisory-database/tree/main/vulns/tensorflow-cpu/PYSEC-2021-456.yaml
• github.com/pypa/advisory-database/tree/main/vulns/tensorflow-gpu/PYSEC-2021-654.yaml
• github.com/pypa/advisory-database/tree/main/vulns/tensorflow/PYSEC-2021-165.yaml
• github.com/tensorflow/tensorflow