CVE-2024-56781

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

powerpc/prom_init: Fixup missing powermac #size-cells

On some powermacs escc nodes are missing #size-cells properties, which is deprecated and now triggers a warning at boot since commit 045b14ca5c36 ("of: WARN on deprecated #address-cells/#size-cells handling").

For example:

Missing '#size-cells' in /pci@f2000000/mac-io@c/escc@13000 WARNING: CPU: 0 PID: 0 at drivers/of/base.c:133 ofbusnsizecells+0x98/0x108 Hardware name: PowerMac3,1 7400 0xc0209 PowerMac ... Call Trace: ofbusnsizecells+0x98/0x108 (unreliable) ofbusdefaultcountcells+0x40/0x60 _ofgetaddress+0xc8/0x21c _ofaddresstoresource+0x5c/0x228 pmzinitport+0x5c/0x2ec pmzprobe.isra.0+0x144/0x1e4 pmzconsoleinit+0x10/0x48 consoleinit+0xcc/0x138 startkernel+0x5c4/0x694

As powermacs boot via prom_init it's possible to add the missing properties to the device tree during boot, avoiding the warning. Note that escc-legacy nodes are also missing #size-cells properties, but they are skipped by the macio driver, so leave them alone.

Depends-on: 045b14ca5c36 ("of: WARN on deprecated #address-cells/#size-cells handling")