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

Vulnerability 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.

References

• 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