CVE-2021-47516: Missing Release of Memory after Effective Lifetime

In the Linux kernel, the following vulnerability has been resolved:

nfp: Fix memory leak in nfp_cpp_area_cache_add()

In line 800 (#1), nfp_cpp_area_alloc() allocates and initializes a CPP area structure. But in line 807 (#2), when the cache is allocated failed, this CPP area structure is not freed, which will result in memory leak.

We can fix it by freeing the CPP area when the cache is allocated failed (#2).

792 int nfp_cpp_area_cache_add(struct nfp_cpp *cpp, size_t size) 793 { 794 struct nfp_cpp_area_cache *cache; 795 struct nfp_cpp_area *area;

800 area = nfp_cpp_area_alloc(cpp, NFP_CPP_ID(7, NFP_CPP_ACTION_RW, 0), 801 0, size); // #1: allocates and initializes

802 if (!area) 803 return -ENOMEM;

805 cache = kzalloc(sizeof(*cache), GFP_KERNEL); 806 if (!cache) 807 return -ENOMEM; // #2: missing free

817 return 0; 818 }