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Memory Corruption in Custom Deleter for std::unique_ptr

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BugFind the bug and fix the code

What it should do

Create a resource and return it wrapped in a std::unique_ptr. Example: createResource() -> std::unique_ptr<Resource>

What happens instead

Double free or corruption (out): Aborted (core dumped)

#include <memory>
#include <cstdlib>

struct Resource {
    void* data;
};

std::unique_ptr<Resource, void(*)(Resource*)> createResource() {
    Resource* res = new Resource();
    res->data = malloc(100);
    // Undefined behavior: mixing free() with new
    return std::unique_ptr<Resource, void(*)(Resource*)>(res, [](Resource* r) { free(r); });
}

int main() {
    auto res = createResource();
    return 0;
}

Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).

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This bug belongs to the logic errors pattern

The wrong operator, an inverted condition, a formula the right way round but backwards.

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#include <memory> #include <cstdlib> struct Resource { void* data; }; std::unique_ptr<Resource, void(*)(Resource*)> createResource() { Resource* res = new Resource(); res->data = malloc(100); // Undefined behavior: mixing free() with new return std::unique_ptr<Resource, void(*)(Resource*)>(res, [](Resource* r) { free(r); }); } int main() { auto res = createResource(); return 0; }

Memory Corruption in Custom Deleter for std::unique_ptr

What it should do

What happens instead

More logic errors to practise

Memory Corruption in Custom Deleter for std::unique_ptr

What it should do

What happens instead

More logic errors to practise