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.
References 3
https://git.kernel.org/stable/c/b6b533f83461c3730875cf3ed5ff6362dcb67be9
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f2849b1fd059ec9b3281b771e6ac5aad9feee851
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/fb4d77553841ae85bed9b2cf03351c401e871d85
416baaa9-dc9f-4396-8d5f-8c081fb06d67