medium5.5

CVE-2021-37692

Segfault on strings tensors with mistmatched dimensions, due to Go code

Impact

### Impact Under certain conditions, Go code can trigger a segfault in string deallocation. For string tensors, `C.TF_TString_Dealloc` is called during garbage collection within a finalizer function. However, tensor structure isn't checked until encoding to avoid a performance penalty. The current method for dealloc assumes that encoding succeeded, but segfaults when a string tensor is garbage collected whose encoding failed (e.g., due to mismatched dimensions). To fix this, the call to set the finalizer function is deferred until `NewTensor` returns and, if encoding failed for a string tensor, deallocs are determined based on bytes written. ### Patches We have patched the issue in GitHub commit [8721ba96e5760c229217b594f6d2ba332beedf22](https://github.com/tensorflow/tensorflow/commit/8721ba96e5760c229217b594f6d2ba332beedf22) (merging [#50508](https://github.com/tensorflow/tensorflow/pull/50508)). The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, which is the other affected version. ### 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 externally via a [fixing PR](https://github.com/tensorflow/tensorflow/pull/50508).

Affected packages

Ecosystem	Package	Affected	Fixed in
pip	`tensorflow`	>= 2.5.0rc0, < 2.5.1	2.5.1
pip	`tensorflow-cpu`	>= 2.5.0rc0, < 2.5.1	2.5.1
pip	`tensorflow-gpu`	>= 2.5.0rc0, < 2.5.1	2.5.1

Affected products

Vendor	Product	Affected versions
Google	Tensorflow	from 2.5.0 before 2.6.0

Weakness classification

CWE-20

Impact

Affected packages

Affected products

Weakness classification

References