Integer overflow due to conversion to unsigned

### Impact The implementation of `tf.raw_ops.QuantizeAndDequantizeV4Grad` is vulnerable to an integer overflow issue caused by converting a signed integer value to an unsigned one and then allocating memory based on this value. ```python import tensorflow as tf tf.raw_ops.QuantizeAndDequantizeV4Grad( gradients=[1.0,2.0], input=[1.0,1.0], input_min=[0.0], input_max=[10.0], axis=-100) ``` The [implementation](https://github.com/tensorflow/tensorflow/blob/8d72537c6abf5a44103b57b9c2e22c14f5f49698/tensorflow/core/kernels/quantize_and_dequantize_op.cc#L126) uses the `axis` value as the size argument to `absl::InlinedVector` constructor. But, the constructor uses an unsigned type for the argument, so the implicit conversion transforms the negative value to a large integer. ### Patches We have patched the issue in GitHub commit [96f364a1ca3009f98980021c4b32be5fdcca33a1](https://github.com/tensorflow/tensorflow/commit/96f364a1ca3009f98980021c4b32be5fdcca33a1). The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, and TensorFlow 2.4.3, 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 members of the Aivul Team from Qihoo 360.

CVSS 3.1

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

Severity from

GitHub (reviewed advisory)

Weakness

CWE-681

Also known as

BIT-tensorflow-2021-37645, CVE-2021-37645, PYSEC-2021-267, PYSEC-2021-558, PYSEC-2021-756

• github.com/tensorflow/tensorflow/security/advisories/GHSA-9w2p-5mgw-p94c
• nvd.nist.gov/vuln/detail/CVE-2021-37645
• github.com/tensorflow/tensorflow/commit/96f364a1ca3009f98980021c4b32be5fdcca33a1
• github.com/pypa/advisory-database/tree/main/vulns/tensorflow-cpu/PYSEC-2021-558.yaml
• github.com/pypa/advisory-database/tree/main/vulns/tensorflow-gpu/PYSEC-2021-756.yaml
• github.com/pypa/advisory-database/tree/main/vulns/tensorflow/PYSEC-2021-267.yaml
• github.com/tensorflow/tensorflow