Fix memory leak of mmaplist_t->chunks and allocator mismatch#3479
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ptitSeb merged 1 commit intoptitSeb:mainfrom Feb 9, 2026
Merged
Fix memory leak of mmaplist_t->chunks and allocator mismatch#3479ptitSeb merged 1 commit intoptitSeb:mainfrom
ptitSeb merged 1 commit intoptitSeb:mainfrom
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mmaplist_t->chunks (blocklist_t**) is a heap-allocated pointer array grown via box_realloc in MmaplistAddBlock/MmaplistAddNBlocks. The individual elements chunks[i] point into InternalMmap regions and are correctly freed by InternalMunmap, but the pointer array itself was never freed. DelMmaplist(): add box_free(list->chunks) before box_free(list). This function is called at runtime from RemoveMapping (env.c) on dlclose/munmap, so the leak accumulates over the program lifetime. fini_custommem_helper(): add box_free(head->chunks) before freeing the struct. Remove box_free(mmaplist) which was dead code — mmaplist was already set to NULL before the if(head) block. Also fix allocator mismatch: the struct is allocated via box_calloc in NewMmaplist() but was freed with raw free() instead of box_free(). Verified with valgrind on ARM64: https://github.com/devarajabc/box64_test_cases/tree/main/003_mmaplist_chunks_leak
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Oh, nice find, thanks. |
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mmaplist_t->chunks (blocklist_t**) is a heap-allocated pointer array grown via box_realloc in MmaplistAddBlock/MmaplistAddNBlocks. The individual elements chunks[i] point into InternalMmap regions and are correctly freed by InternalMunmap, but the pointer array itself was never freed.
DelMmaplist(): add box_free(list->chunks) before box_free(list). This function is called at runtime from RemoveMapping (env.c) on dlclose/munmap, so the leak accumulates over the program lifetime.
fini_custommem_helper(): add box_free(head->chunks) before freeing the struct. Remove box_free(mmaplist) which was dead code — mmaplist was already set to NULL before the if(head) block. Also fix allocator mismatch: the struct is allocated via box_calloc in NewMmaplist() but was freed with raw free() instead of box_free().
Verified with valgrind on ARM64:
https://github.com/devarajabc/box64_test_cases/tree/main/003_mmaplist_chunks_leak