On 11/7/2024 5:37 PM, Bryan O'Donoghue wrote:
On 07/11/2024 10:41, Dmitry Baryshkov wrote:
init_codecs() parses the payload received from firmware and . I don't think we can control this part when we have something like this from a malicious firmware payload HFI_PROPERTY_PARAM_CODEC_SUPPORTED HFI_PROPERTY_PARAM_CODEC_SUPPORTED HFI_PROPERTY_PARAM_CODEC_SUPPORTED ... Limiting it to second iteration would restrict the functionality when property HFI_PROPERTY_PARAM_CODEC_SUPPORTED is sent for supported number of codecs.
If you can have a malicious firmware (which is owned and signed by Qualcomm / OEM), then you have to be careful and skip duplicates. So instead of just adding new cap to core->caps, you have to go through that array, check that you are not adding a duplicate (and report a [Firmware Bug] for duplicates), check that there is an empty slot, etc.
Just ignoring the "extra" entries is not enough.
Thinking of something like this
for_each_set_bit(bit, &core->dec_codecs, MAX_CODEC_NUM) { if (core->codecs_count >= MAX_CODEC_NUM) return; cap = &caps[core->codecs_count++]; if (cap->codec == BIT(bit)) --> each code would have unique bitfield return;
+1
This is a more rational argument. If you get a second message, you should surely reinit the whole array i.e. update the array with the new list, as opposed to throwing away the second message because it over-indexes your local storage..
That would be incorrect to overwrite the array with new list, whenever new payload is received.
Regards, Vikash