In the Linux kernel, the following vulnerability has been resolved: net: phylink: correctly validate returned PCS in phylink_inband_caps In phylink_inband_caps(), the PCS returned by mac_select_pcs is only checked if NULL but mac_select_pcs can also return an error pointer. This can cause a kernel panic as phylink_pcs_inband_caps() only checks if passed PCS is not NULL and directly dereference ops from the phylink_pcs struct. Use the IS_ERR_OR_NULL macro to address both case where the returned PCS can be NULL or an error pointer and prevent a kernel panic.
https://git.kernel.org/stable/c/fb4d77553841ae85bed9b2cf03351c401e871d85
https://git.kernel.org/stable/c/f2849b1fd059ec9b3281b771e6ac5aad9feee851
https://git.kernel.org/stable/c/b6b533f83461c3730875cf3ed5ff6362dcb67be9