CVE-2026-64165

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

ARM: integrator: Fix early initialization

Starting with commit bdb249fce9ad4 ("ARM: integrator: read counter using

syscon/regmap"), intcp_init_early calls syscon_regmap_lookup_by_compatible

which in turn calls of_syscon_register. This function allocates memory.

Since the memory management code has not been initialized at that time,

the call always fails. It either returns -ENOMEM or crashes as follows.

Unable to handle kernel NULL pointer dereference at virtual address 0000000c when read

[0000000c] *pgd=00000000

Internal error: Oops: 5 [#1] ARM

Modules linked in:

CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.15.0-rc5-00026-g5fcc9bf84ee5 #1 PREEMPT

Hardware name: ARM Integrator/CP (Device Tree)

PC is at __kmalloc_cache_noprof+0xec/0x39c

LR is at __kmalloc_cache_noprof+0x34/0x39c

...

Call trace:

__kmalloc_cache_noprof from of_syscon_register+0x7c/0x310

of_syscon_register from device_node_get_regmap+0xa4/0xb0

device_node_get_regmap from intcp_init_early+0xc/0x40

intcp_init_early from start_kernel+0x60/0x688

start_kernel from 0x0

The crash is seen due to a dereferenced pointer which is not supposed to be

NULL but is NULL if the memory management subsystem has not been

initialized. The crash is not seen with all versions of gcc. Some versions

such as gcc 9.x apparently do not dereference the pointer, presumably if

tracing is disabled. The problem has been reproduced with gcc 10.x, 11.x,

and 13.x. Either case, if the crash is not seen, the call to

syscon_regmap_lookup_by_compatible returns -ENOMEM, and

sched_clock_register is never called.

Fix the problem by moving the early initialization code into the standard

machine initialization code.