Commit 58ee5f4e61

LemonBoy <thatlemon@gmail.com>
2020-09-20 00:10:53
std: Fix metadata corruption in HeapAllocator
HeapAllocator stores the pointer returned by HeapAlloc right after the data block and, after the recent allocator refactoring, the space for this pointer was not taken into account in the calculation of the final block size. Fixes #5830
master
1 parent f92d01c
Changed files (1)
lib
std
heap.zig
lib/std/heap.zig
@@ -489,7 +489,7 @@ pub const HeapAllocator = switch (builtin.os.tag) {
                 const full_len = os.windows.kernel32.HeapSize(heap_handle, 0, ptr);
                 assert(full_len != std.math.maxInt(usize));
                 assert(full_len >= amt);
-                break :init mem.alignBackwardAnyAlign(full_len - (aligned_addr - root_addr), len_align);
+                break :init mem.alignBackwardAnyAlign(full_len - (aligned_addr - root_addr) - @sizeOf(usize), len_align);
             };
             const buf = @intToPtr([*]u8, aligned_addr)[0..return_len];
             getRecordPtr(buf).* = root_addr;