In the Linux kernel, the following vulnerability has been resolved:
drm/vc4: fix krealloc() memory leak
Don't just overwrite the original pointer passed to krealloc() with its return value without checking latter:
MEM = krealloc(MEM, SZ, GFP);
If krealloc() returns NULL, that erases the pointer to the still allocated memory, hence leaks this memory. Instead, use a temporary variable, check it's not NULL and only then assign it to the original pointer:
TMP = krealloc(MEM, SZ, GFP); if (!TMP) return; MEM = TMP;
While on it, use krealloc_array().