Description

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 of_bus_n_size_cells+0x98/0x108
Hardware name: PowerMac3,1 7400 0xc0209 PowerMac
...
Call Trace:
of_bus_n_size_cells+0x98/0x108 (unreliable)
of_bus_default_count_cells+0x40/0x60
__of_get_address+0xc8/0x21c
__of_address_to_resource+0x5c/0x228
pmz_init_port+0x5c/0x2ec
pmz_probe.isra.0+0x144/0x1e4
pmz_console_init+0x10/0x48
console_init+0xcc/0x138
start_kernel+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")

Classification

CVE ID: CVE-2024-56781

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.07% (scored less or equal to compared to others)

EPSS Date: 2025-02-06 (when was this score calculated)

References

https://git.kernel.org/stable/c/0b94d838018fb0a824e0cd3149034928c99fb1b7
https://git.kernel.org/stable/c/a79a7e3c03ae2a07f68b5f24d5ed549f9799ec89
https://git.kernel.org/stable/c/ee68554d2c03e32077f7b984e5289fdb005036d2
https://git.kernel.org/stable/c/6d5f0453a2228607333bff0c85238a3cb495d194
https://git.kernel.org/stable/c/691284c2cd33ffaa0b35ce53b3286b90621e9dc9
https://git.kernel.org/stable/c/296a109fa77110ba5267fe0e90a26005eecc2726
https://git.kernel.org/stable/c/cf89c9434af122f28a3552e6f9cc5158c33ce50a

Timeline