Fix undefined behaviour in get_num_outputs in CoreAudio driver #594
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See discussion in #591 for details. Basically an incorrect size was being allocated for the CoreAudio buffer list for a device. It was being allocated by a VLA (which already did not quite fit the semantics of the list) and the length calculated could be 0 (instead of the size of the struct with no buffers elements) causing undefined behaviour. This corrects it to allocate the amount of memory required by the CoreAudio framework function and adds a check for the size retrieval and for the dynamic allocation. This change passed UBSan in my test where before the change it did not.
derselbst
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Nov 13, 2019
derselbst
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See discussion in #591 for details. Basically an incorrect size was being allocated for the CoreAudio buffer list for a device. It was being allocated by a VLA (which already did not quite fit the semantics of the list) and the length calculated could be 0 (instead of the size of the struct with no buffers elements) causing undefined behaviour. This corrects it to allocate the amount of memory required by the CoreAudio framework function and adds a check for the size retrieval and for the dynamic allocation. This change passed UBSan in my test where before the change it did not. Fixes #591
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See discussion in #591 for details. Basically an incorrect size was
being allocated for the CoreAudio buffer list for a device. It was being
allocated by a VLA (which already did not quite fit the semantics of the
list) and the length calculated could be 0 (instead of the size of the
struct with no buffers elements) causing undefined behaviour.
This corrects it to allocate the amount of memory required by the
CoreAudio framework function and adds a check for the size retrieval and
for the dynamic allocation. This change passed UBSan in my test where
before the change it did not.
I made the change suggested in #591 and did a quick test (synthesized a MIDI file to CoreAudio output) which passed UBSan. Look over it to make sure there aren't any issues because I made this pretty quickly.
Thanks again!