Subject: CVE-2021-47050: memory: renesas-rpc-if: fix possible NULL pointer dereference of resource

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

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

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

memory: renesas-rpc-if: fix possible NULL pointer dereference of resource

The platform_get_resource_byname() can return NULL which would be
immediately dereferenced by resource_size().  Instead dereference it
after validating the resource.

Addresses-Coverity: Dereference null return value

The Linux kernel CVE team has assigned CVE-2021-47050 to this issue.

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

	Issue introduced in 5.9 with commit ca7d8b980b67 and fixed in 5.10.37 with commit 71bcc1b4a174
	Issue introduced in 5.9 with commit ca7d8b980b67 and fixed in 5.11.21 with commit e16acc3a37f0
	Issue introduced in 5.9 with commit ca7d8b980b67 and fixed in 5.12.4 with commit a74cb41af7db
	Issue introduced in 5.9 with commit ca7d8b980b67 and fixed in 5.13 with commit 59e27d7c94aa

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-2021-47050
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/memory/renesas-rpc-if.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/71bcc1b4a1743534d8abdcb57ff912e6bc390438
	https://git.kernel.org/stable/c/e16acc3a37f09e18835dc5d8014942c2ef6ca957
	https://git.kernel.org/stable/c/a74cb41af7dbe019e4096171f8bc641c7ce910ad
	https://git.kernel.org/stable/c/59e27d7c94aa02da039b000d33c304c179395801