libretro: detect and communicate buffer overflow on save state serialization#2089
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flyinghead merged 2 commits intoflyinghead:masterfrom Oct 21, 2025
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flyinghead
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core/serialize.h
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| public: | ||
| Exception(const char *msg) : std::runtime_error(msg) {} | ||
| }; | ||
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I would prefer to move the existing Deserializer::Exception to the base class SerializeBase so it can be used by both.
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Good call, just pushed that change.
flyinghead
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Oct 20, 2025
| std::vector<int> data(10); | ||
| Serializer ser(buffer.data(), buffer.size()); | ||
| ASSERT_THROW(ser.serialize(data.data(), data.size()), Serializer::Exception); | ||
| } |
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As discussed in Issue #1903, the libretro core uses dynamic sizing for save states. If the size requirements increase over time by the core, then the RetroArch front end will disregard it and only supply the initial lower size provided in
retro_serialize_size(). This creates a scenario where a buffer is passed toretro_serialize()that is not big enough to store all of the necessary data, and will result in a buffer overflow. In these cases, though it appears to succeed in creating the save state, the file itself is incomplete and cannot be successfully loaded. It's possible the overflow can cause other issues but I saw no evidence of this outside of the incomplete save state file.This PR aims to improve the situation by:
This does not fix the underlying issue, but correctly communicates to the front end and the user* that creating the save state failed.
*In testing, it looks like the current version of RA does not actually show an error to the user that a save state failed to save, though it does not say it was successful either like it did before. I plan on filing a PR to make this more visible on the RA front end as well.