Commit 10b76a42 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86-urgent-2026-04-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 fixes from Ingo Molnar:

 - Fix kexec crash on KCOV-instrumented kernels (Aleksandr Nogikh)

 - Fix Geode platform driver on-stack property data use-after-return
   bug (Dmitry Torokhov)

* tag 'x86-urgent-2026-04-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/platform/geode: Fix on-stack property data use-after-return bug
  x86/kexec: Disable KCOV instrumentation after load_segments()
parents 2ab99ad7 b981e9e9

arch/x86/kernel/Makefile

+14 −0
Original line number Diff line number Diff line
@@ -44,6 +44,20 @@ KCOV_INSTRUMENT_unwind_orc.o := n 
KCOV_INSTRUMENT_unwind_frame.o				:= n

KCOV_INSTRUMENT_unwind_guess.o				:= n



# Disable KCOV to prevent crashes during kexec: load_segments() invalidates

# the GS base, which KCOV relies on for per-CPU data.

#

# As KCOV and KEXEC compatibility should be preserved (e.g. syzkaller is

# using it to collect crash dumps during kernel fuzzing), disabling

# KCOV for KEXEC kernels is not an option. Selectively disabling KCOV

# instrumentation for individual affected functions can be fragile, while

# adding more checks to KCOV would slow it down.

#

# As a compromise solution, disable KCOV instrumentation for the whole

# source code file. If its coverage is ever needed, other approaches

# should be considered.

KCOV_INSTRUMENT_machine_kexec_64.o			:= n



CFLAGS_head32.o := -fno-stack-protector

CFLAGS_head64.o := -fno-stack-protector

CFLAGS_irq.o := -I $(src)/../include/asm/trace

arch/x86/mm/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -4,6 +4,8 @@ KCOV_INSTRUMENT_tlb.o := n 
KCOV_INSTRUMENT_mem_encrypt.o		:= n

KCOV_INSTRUMENT_mem_encrypt_amd.o	:= n

KCOV_INSTRUMENT_pgprot.o		:= n

# See the "Disable KCOV" comment in arch/x86/kernel/Makefile.

KCOV_INSTRUMENT_physaddr.o		:= n



KASAN_SANITIZE_mem_encrypt.o		:= n

KASAN_SANITIZE_mem_encrypt_amd.o	:= n

arch/x86/platform/geode/geode-common.c

+18 −6
Original line number Diff line number Diff line
@@ -28,8 +28,10 @@ static const struct software_node geode_gpio_keys_node = { 
	.properties = geode_gpio_keys_props,

};



static struct property_entry geode_restart_key_props[] = {

	{ /* Placeholder for GPIO property */ },

static struct software_node_ref_args geode_restart_gpio_ref;



static const struct property_entry geode_restart_key_props[] = {

	PROPERTY_ENTRY_REF_ARRAY_LEN("gpios", &geode_restart_gpio_ref, 1),

	PROPERTY_ENTRY_U32("linux,code", KEY_RESTART),

	PROPERTY_ENTRY_STRING("label", "Reset button"),

	PROPERTY_ENTRY_U32("debounce-interval", 100),
@@ -64,8 +66,7 @@ int __init geode_create_restart_key(unsigned int pin) 
	struct platform_device *pd;

	int err;



	geode_restart_key_props[0] = PROPERTY_ENTRY_GPIO("gpios",

							 &geode_gpiochip_node,

	geode_restart_gpio_ref = SOFTWARE_NODE_REFERENCE(&geode_gpiochip_node,

							 pin, GPIO_ACTIVE_LOW);



	err = software_node_register_node_group(geode_gpio_keys_swnodes);
@@ -99,6 +100,7 @@ int __init geode_create_leds(const char *label, const struct geode_led *leds, 
	const struct software_node *group[MAX_LEDS + 2] = { 0 };

	struct software_node *swnodes;

	struct property_entry *props;

	struct software_node_ref_args *gpio_refs;

	struct platform_device_info led_info = {

		.name	= "leds-gpio",

		.id	= PLATFORM_DEVID_NONE,
@@ -127,6 +129,12 @@ int __init geode_create_leds(const char *label, const struct geode_led *leds, 
		goto err_free_swnodes;

	}



	gpio_refs = kzalloc_objs(*gpio_refs, n_leds);

	if (!gpio_refs) {

		err = -ENOMEM;

		goto err_free_props;

	}



	group[0] = &geode_gpio_leds_node;

	for (i = 0; i < n_leds; i++) {

		node_name = kasprintf(GFP_KERNEL, "%s:%d", label, i);
@@ -135,9 +143,11 @@ int __init geode_create_leds(const char *label, const struct geode_led *leds, 
			goto err_free_names;

		}



		gpio_refs[i] = SOFTWARE_NODE_REFERENCE(&geode_gpiochip_node,

						       leds[i].pin,

						       GPIO_ACTIVE_LOW);

		props[i * 3 + 0] =

			PROPERTY_ENTRY_GPIO("gpios", &geode_gpiochip_node,

					    leds[i].pin, GPIO_ACTIVE_LOW);

			PROPERTY_ENTRY_REF_ARRAY_LEN("gpios", &gpio_refs[i], 1);

		props[i * 3 + 1] =

			PROPERTY_ENTRY_STRING("linux,default-trigger",

					      leds[i].default_on ?
@@ -171,6 +181,8 @@ int __init geode_create_leds(const char *label, const struct geode_led *leds, 
err_free_names:

	while (--i >= 0)

		kfree(swnodes[i].name);

	kfree(gpio_refs);

err_free_props:

	kfree(props);

err_free_swnodes:

	kfree(swnodes);