Subject: CVE-2022-48723: spi: uniphier: fix reference count leak in uniphier_spi_probe()

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

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

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

spi: uniphier: fix reference count leak in uniphier_spi_probe()

The issue happens in several error paths in uniphier_spi_probe().
When either dma_get_slave_caps() or devm_spi_register_master() returns
an error code, the function forgets to decrease the refcount of both
`dma_rx` and `dma_tx` objects, which may lead to refcount leaks.

Fix it by decrementing the reference count of specific objects in
those error paths.

The Linux kernel CVE team has assigned CVE-2022-48723 to this issue.

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

	Issue introduced in 5.6 with commit 28d1dddc59f6 and fixed in 5.10.99 with commit e895e067d73e
	Issue introduced in 5.6 with commit 28d1dddc59f6 and fixed in 5.15.22 with commit dd00b4f8f768
	Issue introduced in 5.6 with commit 28d1dddc59f6 and fixed in 5.16.8 with commit 447c3d4046d7
	Issue introduced in 5.6 with commit 28d1dddc59f6 and fixed in 5.17 with commit 37c2c83ca4f1

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-2022-48723
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/spi/spi-uniphier.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/e895e067d73e154b1ebc84a124e00831e311d9b0
	https://git.kernel.org/stable/c/dd00b4f8f768d81c3788a8ac88fdb3d745e55ea3
	https://git.kernel.org/stable/c/447c3d4046d7b54052d07d8b27e15e6edea5662c
	https://git.kernel.org/stable/c/37c2c83ca4f1ef4b6908181ac98e18360af89b42