blzut3 / catacombsdl Goto Github PK

So I compiled the release with the following commands:
cmake /catacombsSDL
make

Copied the game data to the directory and I get the following error.

[1]    5563 segmentation fault  ./catacomb

What information do I need to get you to help with this error?

The level decompression has two bugs:

1. the RLE expand routine should halt the cycle when the threshold is reached on the input bytes, not output bytes; beside checking on the size of the output buffer will cause bogus data to be written (since reads will be performed over the intended limit), the last cycle may also write over the buffer
2. there seems to be a bug in the original project - some levels expand to more than the allocated 4096 bytes; one of the levels expand to 4338 bytes.

The _SDL_turnOnPCSpeaker function performs this operation:

	pcPhaseLength = (pcSample*AudioSpec.freq)/(2*PC_BASE_TIMER);

now, pcSample is a 16 bit unsigned, and AudioSpec.freq a 32 bit signed; their product yields a 32 bit signed.

Since pcSample does reach a value of 65535, and AudioSpec.freq can be 48000, the result will overflow the 32 bit signed capacity.

I guess that one of the two should be casted to a 32 bit unsigned, which, conveniently, is also the pcPhaseLength size.

Snippet here.