Subject: CVE-2024-44971: net: dsa: bcm_sf2: Fix a possible memory leak in bcm_sf2_mdio_register()

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

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

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

net: dsa: bcm_sf2: Fix a possible memory leak in bcm_sf2_mdio_register()

bcm_sf2_mdio_register() calls of_phy_find_device() and then
phy_device_remove() in a loop to remove existing PHY devices.
of_phy_find_device() eventually calls bus_find_device(), which calls
get_device() on the returned struct device * to increment the refcount.
The current implementation does not decrement the refcount, which causes
memory leak.

This commit adds the missing phy_device_free() call to decrement the
refcount via put_device() to balance the refcount.

The Linux kernel CVE team has assigned CVE-2024-44971 to this issue.

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

	Issue introduced in 5.10 with commit 771089c2a485 and fixed in 5.10.224 with commit b7b8d9f5e679
	Issue introduced in 5.10 with commit 771089c2a485 and fixed in 5.15.165 with commit c05516c07290
	Issue introduced in 5.10 with commit 771089c2a485 and fixed in 6.1.105 with commit 7feef10768ea
	Issue introduced in 5.10 with commit 771089c2a485 and fixed in 6.6.46 with commit a7d2808d6757
	Issue introduced in 5.10 with commit 771089c2a485 and fixed in 6.10.5 with commit f3d5efe18a11
	Issue introduced in 5.10 with commit 771089c2a485 and fixed in 6.11 with commit e3862093ee93

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-2024-44971
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/dsa/bcm_sf2.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/b7b8d9f5e679af60c94251fd6728dde34be69a71
	https://git.kernel.org/stable/c/c05516c072903f6fb9134b8e7e1ad4bffcdc4819
	https://git.kernel.org/stable/c/7feef10768ea71d468d9bbc1e0d14c461876768c
	https://git.kernel.org/stable/c/a7d2808d67570e6acae45c2a96e0d59986888e4c
	https://git.kernel.org/stable/c/f3d5efe18a11f94150fee8b3fda9d62079af640a
	https://git.kernel.org/stable/c/e3862093ee93fcfbdadcb7957f5f8974fffa806a