Subject: CVE-2020-36781: i2c: imx: fix reference leak when pm_runtime_get_sync fails

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

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

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

i2c: imx: fix reference leak when pm_runtime_get_sync fails

In i2c_imx_xfer() and i2c_imx_remove(), the pm reference count
is not expected to be incremented on return.

However, pm_runtime_get_sync will increment pm reference count
even failed. Forgetting to putting operation will result in a
reference leak here.

Replace it with pm_runtime_resume_and_get to keep usage
counter balanced.

The Linux kernel CVE team has assigned CVE-2020-36781 to this issue.

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

	Issue introduced in 5.7 with commit 3a5ee18d2a32 and fixed in 5.10.37 with commit 3a0cdd336d92
	Issue introduced in 5.7 with commit 3a5ee18d2a32 and fixed in 5.11.21 with commit 1ecc0ebc2ebb
	Issue introduced in 5.7 with commit 3a5ee18d2a32 and fixed in 5.12.4 with commit ff406f6cd09c
	Issue introduced in 5.7 with commit 3a5ee18d2a32 and fixed in 5.13 with commit 47ff617217ca

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-2020-36781
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/i2c/busses/i2c-imx.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/3a0cdd336d92c429b51a79bf4f64b17eafa0325d
	https://git.kernel.org/stable/c/1ecc0ebc2ebbad4a22a670a07d27a21fa0b59c77
	https://git.kernel.org/stable/c/ff406f6cd09c273337ab4854292e4aca48f8affd
	https://git.kernel.org/stable/c/47ff617217ca6a13194fcb35c6c3a0c57c080693