kc3-lang/libxml2

2023-01-31T12:46:30

malloc-fail: Avoid use-after-free after unsuccessful valuePush In xpath.c there's a lot of code like: valuePush(ctxt, xmlCacheNewX()); ... valuePop(ctxt); If xmlCacheNewX fails, no value will be pushed on the stack. If there's no error check in between, valuePop will pop an unrelated value which can lead to use-after-free errors. Instead of trying to fix all call sites, we simply stop popping values if an error was signaled. This requires to change the CHECK_TYPE macro which is often used to determine whether a value can be safely popped. Found with libFuzzer, see #344.