The VDSO isn’t really any third-party code. It’s very surprising for it to do a stack probe. Though obviously it’s possible, and falls on the runtime to handle (so it’s a legit bug).
But.. nearly every “runtime” makes stack assumptions. They usually just have enough slack that it doesn’t matter. E.g. musl has an 80k stack by default — is it still “incredibly broken” if the VDSO needs > 80k? No.
While the VDSO doesn’t have an explicit stack requirement, it’s definitely implicit that it will use a small, reasonable amount.
But.. nearly every “runtime” makes stack assumptions. They usually just have enough slack that it doesn’t matter. E.g. musl has an 80k stack by default — is it still “incredibly broken” if the VDSO needs > 80k? No.
While the VDSO doesn’t have an explicit stack requirement, it’s definitely implicit that it will use a small, reasonable amount.