Subject: CVE-2021-47516: nfp: Fix memory leak in nfp_cpp_area_cache_add()

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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 }

The Linux kernel CVE team has assigned CVE-2021-47516 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 4.11 with commit 4cb584e0ee7d and fixed in 4.14.258 with commit 3e93abcdcec0
	Issue introduced in 4.11 with commit 4cb584e0ee7d and fixed in 4.19.221 with commit eb51f639ef3f
	Issue introduced in 4.11 with commit 4cb584e0ee7d and fixed in 5.4.165 with commit 2e0e072e62fd
	Issue introduced in 4.11 with commit 4cb584e0ee7d and fixed in 5.10.85 with commit 484069b5de9d
	Issue introduced in 4.11 with commit 4cb584e0ee7d and fixed in 5.15.8 with commit f707820c0923
	Issue introduced in 4.11 with commit 4cb584e0ee7d and fixed in 5.16 with commit c56c96303e92

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2021-47516
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/3e93abcdcec0436fbf0b6a88ae806902426895a2
	https://git.kernel.org/stable/c/eb51f639ef3fd5498b7def290ed8681b6aadd9a7
	https://git.kernel.org/stable/c/2e0e072e62fdaf7816220af08e05c020f0fcb77a
	https://git.kernel.org/stable/c/484069b5de9d223cc1c64c6f80389a99cfef51f1
	https://git.kernel.org/stable/c/f707820c09239d6f67699d9b2ff57863cc7905b0
	https://git.kernel.org/stable/c/c56c96303e9289cc34716b1179597b6f470833de