faf6ea6f28
For several of these, we also patch previous releases. PiperOrigin-RevId: 346617124 Change-Id: I0e88fb02e1d7a98a1df3446c7251d3fcdfe3b8fc
48 lines
2.0 KiB
Markdown
48 lines
2.0 KiB
Markdown
## TFSA-2020-031: Write to immutable memory region
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### CVE Number
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CVE-2020-26268
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### Impact
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The `tf.raw_ops.ImmutableConst` operation returns a constant tensor created from
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a memory mapped file which is assumed immutable. However, if the type of the
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tensor is not an integral type, the operation crashes the Python interpreter as
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it tries to write to the memory area:
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```python
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>>> import tensorflow as tf
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>>> with open('/tmp/test.txt','w') as f: f.write('a'*128)
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>>> tf.raw_ops.ImmutableConst(dtype=tf.string,shape=2,
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memory_region_name='/tmp/test.txt')
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```
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If the file is too small, TensorFlow properly returns an error as the memory
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area has fewer bytes than what is needed for the tensor it creates. However, as
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soon as there are enough bytes, the above snippet causes a segmentation fault.
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This is because the alocator used to return the buffer data is not marked as
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returning an opaque handle since the [needed virtual
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method](https://github.com/tensorflow/tensorflow/blob/c1e1fc899ad5f8c725dcbb6470069890b5060bc7/tensorflow/core/framework/typed_allocator.h#L78-L85)
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is [not
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overriden](https://github.com/tensorflow/tensorflow/blob/acdf3c04fcfa767ae8d109b9e1f727ef050dba4d/tensorflow/core/kernels/immutable_constant_op.cc).
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### Patches
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We have patched the issue in GitHub commit
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[c1e1fc899ad5f8c725dcbb6470069890b5060bc7](https://github.com/tensorflow/tensorflow/commit/c1e1fc899ad5f8c725dcbb6470069890b5060bc7)
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and will release TensorFlow 2.4.0 containing the patch. TensorFlow nightly
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packages after this commit will also have the issue resolved.
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Since this issue also impacts TF versions before 2.4, we will patch all releases
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between 1.15 and 2.3 inclusive.
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### For more information
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Please consult [our security
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guide](https://github.com/tensorflow/tensorflow/blob/master/SECURITY.md) for
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more information regarding the security model and how to contact us with issues
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and questions.
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### Attribution
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This vulnerability has been reported by members of the Aivul Team from Qihoo
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360.
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