CVE-2025-21913

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

x86/amd_nb: Use rdmsr_safe() in amd_get_mmconfig_range()

Xen doesn't offer MSR_FAM10H_MMIO_CONF_BASE to all guests. This results

in the following warning:

unchecked MSR access error: RDMSR from 0xc0010058 at rIP: 0xffffffff8101d19f (xen_do_read_msr+0x7f/0xa0)

Call Trace:

xen_read_msr+0x1e/0x30

amd_get_mmconfig_range+0x2b/0x80

quirk_amd_mmconfig_area+0x28/0x100

pnp_fixup_device+0x39/0x50

__pnp_add_device+0xf/0x150

pnp_add_device+0x3d/0x100

pnpacpi_add_device_handler+0x1f9/0x280

acpi_ns_get_device_callback+0x104/0x1c0

acpi_ns_walk_namespace+0x1d0/0x260

acpi_get_devices+0x8a/0xb0

pnpacpi_init+0x50/0x80

do_one_initcall+0x46/0x2e0

kernel_init_freeable+0x1da/0x2f0

kernel_init+0x16/0x1b0

ret_from_fork+0x30/0x50

ret_from_fork_asm+0x1b/0x30

based on quirks for a "PNP0c01" device. Treating MMCFG as disabled is the

right course of action, so no change is needed there.

This was most likely exposed by fixing the Xen MSR accessors to not be

silently-safe.