faf6ea6f28
For several of these, we also patch previous releases. PiperOrigin-RevId: 346617124 Change-Id: I0e88fb02e1d7a98a1df3446c7251d3fcdfe3b8fc
52 lines
2.2 KiB
Markdown
52 lines
2.2 KiB
Markdown
## TFSA-2020-032: Heap out of bounds read in filesystem glob matching
|
|
|
|
### CVE Number
|
|
CVE-2020-26269
|
|
|
|
### Impact
|
|
The general implementation for matching filesystem paths to globbing pattern is
|
|
vulnerable to an access out of bounds of [the array holding the
|
|
directories](https://github.com/tensorflow/tensorflow/blob/458c6260265c46ebaf18052d6c61aea4b6b40926/tensorflow/core/platform/file_system_helper.cc#L127):
|
|
|
|
```cc
|
|
if (!fs->Match(child_path, dirs[dir_index])) { ... }
|
|
```
|
|
|
|
Since `dir_index` is [unconditionaly
|
|
incremented](https://github.com/tensorflow/tensorflow/blob/458c6260265c46ebaf18052d6c61aea4b6b40926/tensorflow/core/platform/file_system_helper.cc#L106)
|
|
outside of the lambda function where the vulnerable pattern occurs, this results
|
|
in an access out of bounds issue under certain scenarios. For example, if
|
|
`/tmp/x` is a directory that only contains a single file `y`, then the following
|
|
snippet will cause a crash due to the out of bounds read:
|
|
|
|
```python
|
|
>>> tf.io.gfile.glob('/tmp/x/')
|
|
Segmentation fault
|
|
```
|
|
|
|
There are multiple invariants and preconditions that are assumed by the parallel
|
|
implementation of `GetMatchingPaths` but are not verified by the PRs introducing
|
|
it ([#40861](https://github.com/tensorflow/tensorflow/pull/40861) and
|
|
[#44310](https://github.com/tensorflow/tensorflow/pull/44310)). Thus, we are
|
|
completely rewriting the implementation to fully specify and validate these.
|
|
|
|
### Patches
|
|
|
|
We have patched the issue in GitHub commit
|
|
[8b5b9dc96666a3a5d27fad7179ff215e3b74b67c](https://github.com/tensorflow/tensorflow/commit/8b5b9dc96666a3a5d27fad7179ff215e3b74b67c)
|
|
and will release TensorFlow 2.4.0 containing the patch. TensorFlow nightly
|
|
packages after this commit will also have the issue resolved.
|
|
|
|
This issue only impacts master branch and the release candidates for TF version
|
|
2.4. The final release of the 2.4 release will be patched.
|
|
|
|
### 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.
|