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

net: sparx5: skip ptp deinit if init was skipped

sparx5 ptp init() returns early on the base lan969x variants because they do not have the SPX5 FEATURE PTP flag. It also returns early when no "ptp" interrupt is described. Unbinding the driver then causes a NULL pointer dereference when cleaning up uninitialized tx skbs queues:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 Call trace: skb queue purge reason+0x68/0x120 (P) sparx5 ptp deinit+0x64/0xc0 mchp sparx5 remove+0x38/0x70 platform remove+0x20/0x30 device remove+0x4c/0x80

Before per-port tx skbs were added, a NULL dereference would have happened when calling ptp clock unregister() on the never-registered PTP clocks.

Fix by returning early in sparx5 ptp deinit() if PTP is not used.