linux-stable.git/drivers/firmware/efi/efi.c, branch linux-rolling-stable

efi: Allocate runtime workqueue before ACPI init

2026-06-01T15:54:21+00:00

commit 13c6da02e767152c9ac4330962247a5e47011035 upstream.

Since commit

  5894cf571e14 ("acpi/prmt: Use EFI runtime sandbox to invoke PRM handlers")

ACPI PRM calls are delegated to a workqueue which runs in a kernel
thread, making it easier to detect and mitigate faulting memory accesses
performed by the firmware.

Rafael reports that such PRM accesses may occur before efisubsys_init()
executes, which is where the workqueue is allocated, leading to NULL
pointer dereferences. Since acpi_init() [which triggers the early PRM
accesses] executes as a subsys_initcall() as well, and has its own
dependencies that may be sensitive to initcall ordering, deferring
acpi_init() is not an option.

So instead, split off the workqueue allocation into its own postcore
initcall, as this is the only missing piece to allow EFI runtime calls
to be made. This ensures that EFI runtime call (including PRM calls) are
accessible to all code running at subsys_initcall() level.

Cc: 
Fixes: 5894cf571e14 ("acpi/prmt: Use EFI runtime sandbox to invoke PRM handlers")
Reviewed-by: Rafael J. Wysocki (Intel) 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Greg Kroah-Hartman

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook

efi: Fix reservation of unaccepted memory table

2026-02-18T10:26:20+00:00

The reserve_unaccepted() function incorrectly calculates the size of the
memblock reservation for the unaccepted memory table. It aligns the
size of the table, but fails to account for cases where the table's
starting physical address (efi.unaccepted) is not page-aligned.

If the table starts at an offset within a page and its end crosses into
a subsequent page that the aligned size does not cover, the end of the
table will not be reserved. This can lead to the table being overwritten
or inaccessible, causing a kernel panic in accept_memory().

This issue was observed when starting Intel TDX VMs with specific memory
sizes (e.g., > 64GB).

Fix this by calculating the end address first (including the unaligned
start) and then aligning it up, ensuring the entire range is covered
by the reservation.

Fixes: 8dbe33956d96 ("efi/unaccepted: Make sure unaccepted table is mapped")
Reported-by: Moritz Sanft 
Signed-off-by: Kiryl Shutsemau (Meta) 
Reviewed-by: Tom Lendacky 
Acked-by: Mike Rapoport (Microsoft) 
Signed-off-by: Ard Biesheuvel

Merge tag 'efi-next-for-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

2026-02-10T04:49:19+00:00

Pull EFI updates from Ard Biesheuvel:

 - Quirk the broken EFI framebuffer geometry on the Valve Steam Deck

 - Capture the EDID information of the primary display also on non-x86
   EFI systems when booting via the EFI stub.

* tag 'efi-next-for-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: Support EDID information
  sysfb: Move edid_info into sysfb_primary_display
  sysfb: Pass sysfb_primary_display to devices
  sysfb: Replace screen_info with sysfb_primary_display
  sysfb: Add struct sysfb_display_info
  efi: sysfb_efi: Reduce number of references to global screen_info
  efi: earlycon: Reduce number of references to global screen_info
  efi: sysfb_efi: Fix efidrmfb and simpledrmfb on Valve Steam Deck
  efi: sysfb_efi: Convert swap width and height quirk to a callback
  efi: sysfb_efi: Fix lfb_linelength calculation when applying quirks
  efi: sysfb_efi: Replace open coded swap with the macro

mm: rename cpu_bitmap field to flexible_array

2026-01-19T20:30:00+00:00

The cpu_bitmap flexible array now contains more than just the cpu_bitmap. 
In preparation for changing the static mm_struct definitions to cover for
the additional space required, change the cpu_bitmap type from "unsigned
long" to "char", require an unsigned long alignment of the flexible array,
and rename the field from "cpu_bitmap" to "flexible_array".

Introduce the MM_STRUCT_FLEXIBLE_ARRAY_INIT macro to statically initialize
the flexible array.  This covers the init_mm and efi_mm static
definitions.

This is a preparation step for fixing the missing mm_cid size for static
mm_struct definitions.

Link: https://lkml.kernel.org/r/20251224173358.647691-3-mathieu.desnoyers@efficios.com
Fixes: af7f588d8f73 ("sched: Introduce per-memory-map concurrency ID")
Signed-off-by: Mathieu Desnoyers 
Reviewed-by: Thomas Gleixner 
Cc: Mark Brown 
Cc: Aboorva Devarajan 
Cc: Al Viro 
Cc: Baolin Wang 
Cc: Christan König 
Cc: Christian Brauner 
Cc: Christoph Lameter 
Cc: David Hildenbrand 
Cc: David Rientjes 
Cc: Dennis Zhou 
Cc: Johannes Weiner 
Cc: "Liam R . Howlett" 
Cc: Lorenzo Stoakes 
Cc: Martin Liu 
Cc: Masami Hiramatsu 
Cc: Mateusz Guzik 
Cc: Matthew Wilcox 
Cc: Miaohe Lin 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: "Paul E. McKenney" 
Cc: Roman Gushchin 
Cc: SeongJae Park 
Cc: Shakeel Butt 
Cc: Steven Rostedt 
Cc: Suren Baghdasaryan 
Cc: Sweet Tea Dorminy 
Cc: Tejun Heo 
Cc: Vlastimil Babka 
Cc: Wei Yang 
Cc: Yu Zhao 
Cc: Peter Zijlstra (Intel) 
Cc: 
Signed-off-by: Andrew Morton

efi: Wipe INITRD config table from memory after consumption

2026-01-08T11:41:38+00:00

When the EFI stub itself loads the initrd and puts it in memory (rather
than simply passing on a struct boot_params or device tree that already
carries initrd information), it exposes this information to the core
kernel via a INITRD configuration table.

Given that config tables are preserved across kexec, this means that
subsequent kexec boots will observe the same information, even though it
most likely has become stale by that point. On x86, this information is
usually superseded by the initrd info passed via bootparams, in which
case this stale information is simply ignored. However, when performing
a kexec boot without passing an initrd, the loader falls back to this
stale information and explodes.

So wipe the base and size from the INITRD config table as soon as it has
been consumed. This fixes the issue for kexec on all EFI architectures.

Reported-by: James Le Cuirot 
Tested-by: James Le Cuirot 
Acked-by: H. Peter Anvin (Intel) 
Link: https://lore.kernel.org/all/20251126173209.374755-2-chewi@gentoo.org
Signed-off-by: Ard Biesheuvel

arm64: efi: Fix NULL pointer dereference by initializing user_ns

2025-12-24T20:32:57+00:00

Linux 6.19-rc2 (9448598b22c5 ("Linux 6.19-rc2")) is crashing with a NULL
pointer dereference on arm64 hosts:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000000000c8
   pc : cap_capable (security/commoncap.c:82 security/commoncap.c:128)
   Call trace:
    cap_capable (security/commoncap.c:82 security/commoncap.c:128) (P)
    security_capable (security/security.c:?)
    ns_capable_noaudit (kernel/capability.c:342 kernel/capability.c:381)
    __ptrace_may_access (./include/linux/rcupdate.h:895 kernel/ptrace.c:326)
    ptrace_may_access (kernel/ptrace.c:353)
    do_task_stat (fs/proc/array.c:467)
    proc_tgid_stat (fs/proc/array.c:673)
    proc_single_show (fs/proc/base.c:803)

I've bissected the problem to commit a5baf582f4c0 ("arm64/efi: Call EFI
runtime services without disabling preemption").

>From my analyzes, the crash occurs because efi_mm lacks a user_ns field
initialization. This was previously harmless, but commit a5baf582f4c0
("arm64/efi: Call EFI runtime services without disabling preemption")
changed the EFI runtime call path to use kthread_use_mm(&efi_mm), which
temporarily adopts efi_mm as the current mm for the calling kthread.

When a thread has an active mm, LSM hooks like cap_capable() expect
mm->user_ns to be valid for credential checks. With efi_mm.user_ns being
NULL, capability checks during possible /proc access dereference the
NULL pointer and crash.

Fix by initializing efi_mm.user_ns to &init_user_ns.

Fixes: a5baf582f4c0 ("arm64/efi: Call EFI runtime services without disabling preemption")
Signed-off-by: Breno Leitao 
Acked-by: Rik van Riel 
Signed-off-by: Ard Biesheuvel

efi: Support EDID information

2025-12-16T13:40:51+00:00

In the EFI config table, rename LINUX_EFI_SCREEN_INFO_TABLE_GUID to
LINUX_EFI_PRIMARY_DISPLAY_TABLE_GUID. Read sysfb_primary_display from
the entry. In addition to the screen_info, the entry now also contains
EDID information.

In libstub, replace struct screen_info with struct sysfb_display_info
from the kernel's sysfb_primary_display and rename functions
accordingly.  Transfer it to the runtime kernel using the kernel's
global state or the LINUX_EFI_PRIMARY_DISPLAY_TABLE_GUID config-table
entry.

With CONFIG_FIRMWARE_EDID=y, libstub now transfers the GOP device's EDID
information to the kernel. If CONFIG_FIRMWARE_EDID=n, EDID information
is disabled. Make the Kconfig symbol CONFIG_FIRMWARE_EDID available with
EFI. Setting the value to 'n' disables EDID support.

Also rename screen_info.c to primary_display.c and adapt the contained
comment according to the changes.

Link: https://lore.kernel.org/all/20251126160854.553077-8-tzimmermann@suse.de/
Signed-off-by: Thomas Zimmermann 
[ardb: depend on EFI_GENERIC_STUB not EFI, fix conflicts after dropping
       the preceding patch from the series]
Signed-off-by: Ard Biesheuvel

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2025-12-03T01:03:55+00:00

Pull arm64 updates from Catalin Marinas:
 "These are the arm64 updates for 6.19.

  The biggest part is the Arm MPAM driver under drivers/resctrl/.
  There's a patch touching mm/ to handle spurious faults for huge pmd
  (similar to the pte version). The corresponding arm64 part allows us
  to avoid the TLB maintenance if a (huge) page is reused after a write
  fault. There's EFI refactoring to allow runtime services with
  preemption enabled and the rest is the usual perf/PMU updates and
  several cleanups/typos.

  Summary:

  Core features:

   - Basic Arm MPAM (Memory system resource Partitioning And Monitoring)
     driver under drivers/resctrl/ which makes use of the fs/rectrl/ API

  Perf and PMU:

   - Avoid cycle counter on multi-threaded CPUs

   - Extend CSPMU device probing and add additional filtering support
     for NVIDIA implementations

   - Add support for the PMUs on the NoC S3 interconnect

   - Add additional compatible strings for new Cortex and C1 CPUs

   - Add support for data source filtering to the SPE driver

   - Add support for i.MX8QM and "DB" PMU in the imx PMU driver

  Memory managemennt:

   - Avoid broadcast TLBI if page reused in write fault

   - Elide TLB invalidation if the old PTE was not valid

   - Drop redundant cpu_set_*_tcr_t0sz() macros

   - Propagate pgtable_alloc() errors outside of __create_pgd_mapping()

   - Propagate return value from __change_memory_common()

  ACPI and EFI:

   - Call EFI runtime services without disabling preemption

   - Remove unused ACPI function

  Miscellaneous:

   - ptrace support to disable streaming on SME-only systems

   - Improve sysreg generation to include a 'Prefix' descriptor

   - Replace __ASSEMBLY__ with __ASSEMBLER__

   - Align register dumps in the kselftest zt-test

   - Remove some no longer used macros/functions

   - Various spelling corrections"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (94 commits)
  arm64/mm: Document why linear map split failure upon vm_reset_perms is not problematic
  arm64/pageattr: Propagate return value from __change_memory_common
  arm64/sysreg: Remove unused define ARM64_FEATURE_FIELD_BITS
  KVM: arm64: selftests: Consider all 7 possible levels of cache
  KVM: arm64: selftests: Remove ARM64_FEATURE_FIELD_BITS and its last user
  arm64: atomics: lse: Remove unused parameters from ATOMIC_FETCH_OP_AND macros
  Documentation/arm64: Fix the typo of register names
  ACPI: GTDT: Get rid of acpi_arch_timer_mem_init()
  perf: arm_spe: Add support for filtering on data source
  perf: Add perf_event_attr::config4
  perf/imx_ddr: Add support for PMU in DB (system interconnects)
  perf/imx_ddr: Get and enable optional clks
  perf/imx_ddr: Move ida_alloc() from ddr_perf_init() to ddr_perf_probe()
  dt-bindings: perf: fsl-imx-ddr: Add compatible string for i.MX8QM, i.MX8QXP and i.MX8DXL
  arm64: remove duplicate ARCH_HAS_MEM_ENCRYPT
  arm64: mm: use untagged address to calculate page index
  MAINTAINERS: new entry for MPAM Driver
  arm_mpam: Add kunit tests for props_mismatch()
  arm_mpam: Add kunit test for bitmap reset
  arm_mpam: Add helper to reset saved mbwu state
  ...

efi: Add missing static initializer for efi_mm::cpus_allowed_lock

2025-11-11T18:59:22+00:00

Initialize the cpus_allowed_lock struct member of efi_mm.

Cc: stable@vger.kernel.org
Signed-off-by: Ard Biesheuvel 
Acked-by: Catalin Marinas 
Signed-off-by: Catalin Marinas