TFLite's expand_dims.cc
contains a vulnerability which allows reading one element outside of bounds of heap allocated data:
if (axis < 0) {
axis = input_dims.size + 1 + axis;
}
TF_LITE_ENSURE(context, axis <= input_dims.size);
TfLiteIntArray* output_dims = TfLiteIntArrayCreate(input_dims.size + 1);
for (int i = 0; i < output_dims->size; ++i) {
if (i < axis) {
output_dims->data[i] = input_dims.data[i];
} else if (i == axis) {
output_dims->data[i] = 1;
} else {
output_dims->data[i] = input_dims.data[i - 1];
}
}
If axis
is a large negative value (e.g., -100000
), then after the first if
it would still be negative. The check following the if
statement will pass and the for
loop would read one element before the start of input_dims.data
(when i = 0
).
We have patched the issue in GitHub commit d94ffe08a65400f898241c0374e9edc6fa8ed257.
The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, as these are also affected and still in supported range.
Please consult our security guide for more information regarding the security model and how to contact us with issues and questions.
This vulnerability has been reported by Yakun Zhang of Baidu Security.