kernel/linux.git/drivers/acpi, branch v6.12.80

ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()

2026-04-02T11:09:40+00:00

[ Upstream commit f6484cadbcaf26b5844b51bd7307a663dda48ef6 ] When ec_install_handlers() returns -EPROBE_DEFER on reduced-hardware platforms, it has already started the EC and installed the address space handler with the struct acpi_ec pointer as handler context. However, acpi_ec_setup() propagates the error without any cleanup. The caller acpi_ec_add() then frees the struct acpi_ec for non-boot instances, leaving a dangling handler context in ACPICA. Any subsequent AML evaluation that accesses an EC OpRegion field dispatches into acpi_ec_space_handler() with the freed pointer, causing a use-after-free: BUG: KASAN: slab-use-after-free in mutex_lock (kernel/locking/mutex.c:289) Write of size 8 at addr ffff88800721de38 by task init/1 Call Trace: mutex_lock (kernel/locking/mutex.c:289) acpi_ec_space_handler (drivers/acpi/ec.c:1362) acpi_ev_address_space_dispatch (drivers/acpi/acpica/evregion.c:293) acpi_ex_access_region (drivers/acpi/acpica/exfldio.c:246) acpi_ex_field_datum_io (drivers/acpi/acpica/exfldio.c:509) acpi_ex_extract_from_field (drivers/acpi/acpica/exfldio.c:700) acpi_ex_read_data_from_field (drivers/acpi/acpica/exfield.c:327) acpi_ex_resolve_node_to_value (drivers/acpi/acpica/exresolv.c:392) Allocated by task 1: acpi_ec_alloc (drivers/acpi/ec.c:1424) acpi_ec_add (drivers/acpi/ec.c:1692) Freed by task 1: kfree (mm/slub.c:6876) acpi_ec_add (drivers/acpi/ec.c:1751) The bug triggers on reduced-hardware EC platforms (ec->gpe < 0) when the GPIO IRQ provider defers probing. Once the stale handler exists, any unprivileged sysfs read that causes AML to touch an EC OpRegion (battery, thermal, backlight) exercises the dangling pointer. Fix this by calling ec_remove_handlers() in the error path of acpi_ec_setup() before clearing first_ec. ec_remove_handlers() checks each EC_FLAGS_* bit before acting, so it is safe to call regardless of how far ec_install_handlers() progressed: -ENODEV (handler not installed): only calls acpi_ec_stop() -EPROBE_DEFER (handler installed): removes handler, stops EC Fixes: 03e9a0e05739 ("ACPI: EC: Consolidate event handler installation code") Reported-by: Xiang Mei Signed-off-by: Weiming Shi Link: https://patch.msgid.link/20260324165458.1337233-2-bestswngs@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: processor: Fix previous acpi_processor_errata_piix4() fix

2026-03-25T10:08:54+00:00

[ Upstream commit bf504b229cb8d534eccbaeaa23eba34c05131e25 ] After commi f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()"), device pointers may be dereferenced after dropping references to the device objects pointed to by them, which may cause a use-after-free to occur. Moreover, debug messages about enabling the errata may be printed if the errata flags corresponding to them are unset. Address all of these issues by moving message printing to the points in the code where the errata flags are set. Fixes: f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()") Reported-by: Guenter Roeck Closes: https://lore.kernel.org/linux-acpi/938e2206-def5-4b7a-9b2c-d1fd37681d8a@roeck-us.net/ Reviewed-by: Guenter Roeck Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/5975693.DvuYhMxLoT@rafael.j.wysocki Signed-off-by: Sasha Levin

ACPI: OSL: fix __iomem type on return from acpi_os_map_generic_address()

2026-03-25T10:08:30+00:00

[ Upstream commit 393815f57651101f1590632092986d1d5a3a41bd ] The pointer returned from acpi_os_map_generic_address() is tagged with __iomem, so make the rv it is returned to also of void __iomem * type. Fixes the following sparse warning: drivers/acpi/osl.c:1686:20: warning: incorrect type in assignment (different address spaces) drivers/acpi/osl.c:1686:20: expected void *rv drivers/acpi/osl.c:1686:20: got void [noderef] __iomem * Fixes: 6915564dc5a8 ("ACPI: OSL: Change the type of acpi_os_map_generic_address() return value") Signed-off-by: Ben Dooks [ rjw: Subject tweak, added Fixes tag ] Link: https://patch.msgid.link/20260311105835.463030-1-ben.dooks@codethink.co.uk Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: OSI: Add DMI quirk for Acer Aspire One D255

2026-03-25T10:08:24+00:00

[ Upstream commit 5ede90206273ff156a778254f0f972a55e973c89 ] The screen backlight turns off during boot (specifically during udev device initialization) when returning true for _OSI("Windows 2009"). Analyzing the device's DSDT reveals that the firmware takes a different code path when Windows 7 is reported, which leads to the backlight shutoff. Add a DMI quirk to invoke dmi_disable_osi_win7 for this model. Signed-off-by: Sofia Schneider Link: https://patch.msgid.link/20260223025240.518509-1-sofia@schn.dev Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: PM: Save NVS memory on Lenovo G70-35

2026-03-25T10:08:24+00:00

[ Upstream commit 023cd6d90f8aa2ef7b72d84be84a18e61ecebd64 ] [821d6f0359b0614792ab8e2fb93b503e25a65079] prevented machines produced later than 2012 from saving NVS region to accelerate S3. Despite being made after 2012, Lenovo G70-35 still needs NVS memory saving during S3. A quirk is introduced for this platform. Signed-off-by: Piotr Mazek [ rjw: Subject adjustment ] Link: https://patch.msgid.link/GV2PPF3CD5B63CC2442EE3F76F8443EAD90D499A@GV2PPF3CD5B63CC.EURP251.PROD.OUTLOOK.COM Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: APEI: GHES: Disable KASAN instrumentation when compile testing with clang < 18

2026-03-13T16:20:37+00:00

[ Upstream commit b584bfbd7ec417f257f651cc00a90c66e31dfbf1 ] After a recent innocuous change to drivers/acpi/apei/ghes.c, building ARCH=arm64 allmodconfig with clang-17 or older (which has both CONFIG_KASAN=y and CONFIG_WERROR=y) fails with: drivers/acpi/apei/ghes.c:902:13: error: stack frame size (2768) exceeds limit (2048) in 'ghes_do_proc' [-Werror,-Wframe-larger-than] 902 | static void ghes_do_proc(struct ghes *ghes, | ^ A KASAN pass that removes unneeded stack instrumentation, enabled by default in clang-18 [1], drastically improves stack usage in this case. To avoid the warning in the common allmodconfig case when it can break the build, disable KASAN for ghes.o when compile testing with clang-17 and older. Disabling KASAN outright may hide legitimate runtime issues, so live with the warning in that case; the user can either increase the frame warning limit or disable -Werror, which they should probably do when debugging with KASAN anyways. Closes: https://github.com/ClangBuiltLinux/linux/issues/2148 Link: https://github.com/llvm/llvm-project/commit/51fbab134560ece663517bf1e8c2a30300d08f1a [1] Signed-off-by: Nathan Chancellor Cc: All applicable Link: https://patch.msgid.link/20260114-ghes-avoid-wflt-clang-older-than-18-v1-1-9c8248bfe4f4@kernel.org Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: x86: Force enabling of PWM2 on the Yogabook YB1-X90

2026-03-04T12:21:27+00:00

[ Upstream commit a8c975302868c716afef0f50467bebbd069a35b8 ] The PWM2 on YB1-X90 tablets is used for keyboard backlight control but it is disabled in the ACPI DSDT table. Add it to the override_status_ids list to allow keyboard function control driver (drivers/platform/x86/lenovo/yogabook.c) to use it. Signed-off-by: Yauhen Kharuzhy Link: https://patch.msgid.link/20260211222242.4101162-1-jekhor@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: battery: fix incorrect charging status when current is zero

2026-03-04T12:20:56+00:00

[ Upstream commit bb1256e0ddc7e9e406164319769b9f8d8389f056 ] On some laptops, such as the Huawei Matebook series, the embedded controller continues to report "Charging" status even when the charge threshold is reached and no current is being drawn. This incorrect reporting prevents the system from switching to battery power profiles, leading to significantly higher power (e.g., 18W instead of 7W during browsing) and missed remaining battery time estimation. Validate the "Charging" state by checking if rate_now is zero. If the hardware reports charging but the current is zero, report "Not Charging" to user space. Signed-off-by: Ata İlhan Köktürk [ rjw: Whitespace fix, braces added to an inner if (), new comment rewrite ] [ rjw: Changelog edits ] Link: https://patch.msgid.link/20260129144856.43058-1-atailhan2006@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: x86: s2idle: Invoke Microsoft _DSM Function 9 (Turn On Display)

2026-03-04T12:20:55+00:00

[ Upstream commit 229ecbaac6b31f89c554b77eb407377a5eade7d4 ] Windows 11, version 22H2 introduced a new function index (Function 9) to the Microsoft LPS0 _DSM, titled "Turn On Display Notification". According to Microsoft documentation, this function signals to the system firmware that the OS intends to turn on the display when exiting Modern Standby. This allows the firmware to release Power Limits (PLx) earlier. Crucially, this patch fixes a functional issue observed on the Lenovo Yoga Slim 7i Aura (15ILL9), where system fans and keyboard backlights fail to resume after suspend. Investigation linked shows the EC on this device turns off these components during sleep but requires the Function 9 notification to wake them up again. This patch defines the new function index (ACPI_MS_TURN_ON_DISPLAY) and invokes it in acpi_s2idle_restore_early_lps0(). The execution order is updated to match the logic of an "intent" signal: 1. LPS0 Exit (Function 6) 2. Turn On Display Intent (Function 9) 3. Modern Standby Exit (Function 8) 4. Screen On (Function 4) Invoking Function 9 before the Modern Standby Exit ensures the firmware has time to restore power rails and functionality (like fans) before the software fully exits the sleep state. Link: https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby-firmware-notifications#turn-on-display-notification-function-9 Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220505 Suggested-by: Antheas Kapenekakis Signed-off-by: Jakob Riemenschneider Link: https://patch.msgid.link/20260127200121.1292216-1-riemenschneiderjakob@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPICA: Abort AML bytecode execution when executing AML_FATAL_OP

2026-03-04T12:20:54+00:00

[ Upstream commit 026ad376a6a48538b576f3589331daa94daae6f0 ] The ACPI specification states that when executing AML_FATAL_OP, the OS should log the fatal error event and shutdown in a timely fashion. Windows complies with this requirement by immediatly entering a Bso_d, effectively aborting the execution of the AML bytecode in question. ACPICA however might continue with the AML bytecode execution should acpi_os_signal() simply return AE_OK. This will cause issues because ACPI BIOS implementations might assume that the Fatal() operator does not return. Fix this by aborting the AML bytecode execution in such a case by returning AE_ERROR. Also turn struct acpi_signal_fatal_info into a local variable because of its small size (12 bytes) and to ensure that acpi_os_signal() always receives valid information about the fatal ACPI BIOS error. Link: https://github.com/acpica/acpica/commit/d516c7758ba6 Signed-off-by: Armin Wolf Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/3325491.5fSG56mABF@rafael.j.wysocki Signed-off-by: Sasha Levin