linux-stable.git/drivers/firmware, branch linux-5.10.y

efi/mokvar-table: Avoid repeated map/unmap of the same page

2026-04-18T08:31:10+00:00

[ Upstream commit e3cf2d91d0583cae70aeb512da87e3ade25ea912 ]

Tweak the logic that traverses the MOKVAR UEFI configuration table to
only unmap the entry header and map the next one if they don't live in
the same physical page.

Link: https://lore.kernel.org/all/8f085931-3e9d-4386-9209-1d6c95616327@uncooperative.org/
Tested-By: Peter Jones 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Sasha Levin

x86/efi: defer freeing of boot services memory

2026-04-18T08:30:51+00:00

commit a4b0bf6a40f3c107c67a24fbc614510ef5719980 upstream.

efi_free_boot_services() frees memory occupied by EFI_BOOT_SERVICES_CODE
and EFI_BOOT_SERVICES_DATA using memblock_free_late().

There are two issue with that: memblock_free_late() should be used for
memory allocated with memblock_alloc() while the memory reserved with
memblock_reserve() should be freed with free_reserved_area().

More acutely, with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
efi_free_boot_services() is called before deferred initialization of the
memory map is complete.

Benjamin Herrenschmidt reports that this causes a leak of ~140MB of
RAM on EC2 t3a.nano instances which only have 512MB or RAM.

If the freed memory resides in the areas that memory map for them is
still uninitialized, they won't be actually freed because
memblock_free_late() calls memblock_free_pages() and the latter skips
uninitialized pages.

Using free_reserved_area() at this point is also problematic because
__free_page() accesses the buddy of the freed page and that again might
end up in uninitialized part of the memory map.

Delaying the entire efi_free_boot_services() could be problematic
because in addition to freeing boot services memory it updates
efi.memmap without any synchronization and that's undesirable late in
boot when there is concurrency.

More robust approach is to only defer freeing of the EFI boot services
memory.

Split efi_free_boot_services() in two. First efi_unmap_boot_services()
collects ranges that should be freed into an array then
efi_free_boot_services() later frees them after deferred init is complete.

Link: https://lore.kernel.org/all/ec2aaef14783869b3be6e3c253b2dcbf67dbc12a.camel@kernel.crashing.org
Fixes: 916f676f8dc0 ("x86, efi: Retain boot service code until after switching to virtual mode")
Cc: 
Signed-off-by: Mike Rapoport (Microsoft) 
Reviewed-by: Benjamin Herrenschmidt 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Greg Kroah-Hartman

EFI/CPER: don't go past the ARM processor CPER record buffer

2026-03-04T12:19:53+00:00

[ Upstream commit eae21beecb95a3b69ee5c38a659f774e171d730e ]

There's a logic inside GHES/CPER to detect if the section_length
is too small, but it doesn't detect if it is too big.

Currently, if the firmware receives an ARM processor CPER record
stating that a section length is big, kernel will blindly trust
section_length, producing a very long dump. For instance, a 67
bytes record with ERR_INFO_NUM set 46198 and section length
set to 854918320 would dump a lot of data going a way past the
firmware memory-mapped area.

Fix it by adding a logic to prevent it to go past the buffer
if ERR_INFO_NUM is too big, making it report instead:

	[Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 1
	[Hardware Error]: event severity: recoverable
	[Hardware Error]:  Error 0, type: recoverable
	[Hardware Error]:   section_type: ARM processor error
	[Hardware Error]:   MIDR: 0xff304b2f8476870a
	[Hardware Error]:   section length: 854918320, CPER size: 67
	[Hardware Error]:   section length is too big
	[Hardware Error]:   firmware-generated error record is incorrect
	[Hardware Error]:   ERR_INFO_NUM is 46198

Signed-off-by: Mauro Carvalho Chehab 
Reviewed-by: Jonathan Cameron 
Acked-by: Ard Biesheuvel 
Reviewed-by: Hanjun Guo 
[ rjw: Subject and changelog tweaks ]
Link: https://patch.msgid.link/41cd9f6b3ace3cdff7a5e864890849e4b1c58b63.1767871950.git.mchehab+huawei@kernel.org
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

EFI/CPER: don't dump the entire memory region

2026-03-04T12:19:53+00:00

[ Upstream commit 55cc6fe5716f678f06bcb95140882dfa684464ec ]

The current logic at cper_print_fw_err() doesn't check if the
error record length is big enough to handle offset. On a bad firmware,
if the ofset is above the actual record, length -= offset will
underflow, making it dump the entire memory.

The end result can be:

 - the logic taking a lot of time dumping large regions of memory;
 - data disclosure due to the memory dumps;
 - an OOPS, if it tries to dump an unmapped memory region.

Fix it by checking if the section length is too small before doing
a hex dump.

Signed-off-by: Mauro Carvalho Chehab 
Reviewed-by: Jonathan Cameron 
Acked-by: Ard Biesheuvel 
Reviewed-by: Hanjun Guo 
[ rjw: Subject tweaks ]
Link: https://patch.msgid.link/1752b5ba63a3e2f148ddee813b36c996cc617e86.1767871950.git.mchehab+huawei@kernel.org
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

efi/cper: Fix cper_bits_to_str buffer handling and return value

2026-01-19T12:12:12+00:00

commit d7f1b4bdc7108be1b178e1617b5f45c8918e88d7 upstream.

The return value calculation was incorrect: `return len - buf_size;`
Initially `len = buf_size`, then `len` decreases with each operation.
This results in a negative return value on success.

Fix by returning `buf_size - len` which correctly calculates the actual
number of bytes written.

Fixes: a976d790f494 ("efi/cper: Add a new helper function to print bitmasks")
Signed-off-by: Morduan Zang 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Greg Kroah-Hartman

firmware: imx: scu-irq: Set mu_resource_id before get handle

2026-01-19T12:12:12+00:00

commit ff3f9913bc0749364fbfd86ea62ba2d31c6136c8 upstream.

mu_resource_id is referenced in imx_scu_irq_get_status() and
imx_scu_irq_group_enable() which could be used by other modules, so
need to set correct value before using imx_sc_irq_ipc_handle in
SCU API call.

Reviewed-by: Frank Li 
Signed-off-by: Peng Fan 
Signed-off-by: Shawn Guo 
Fixes: 81fb53feb66a ("firmware: imx: scu-irq: Init workqueue before request mbox channel")
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

firmware: imx: scu-irq: Init workqueue before request mbox channel

2026-01-19T12:11:45+00:00

[ Upstream commit 81fb53feb66a3aefbf6fcab73bb8d06f5b0c54ad ]

With mailbox channel requested, there is possibility that interrupts may
come in, so need to make sure the workqueue is initialized before
the queue is scheduled by mailbox rx callback.

Reviewed-by: Frank Li 
Signed-off-by: Peng Fan 
Signed-off-by: Shawn Guo 
Signed-off-by: Sasha Levin

efi/cper: align ARM CPER type with UEFI 2.9A/2.10 specs

2026-01-19T12:11:39+00:00

[ Upstream commit 96b010536ee020e716d28d9b359a4bcd18800aeb ]

Up to UEFI spec 2.9, the type byte of CPER struct for ARM processor
was defined simply as:

Type at byte offset 4:

	- Cache error
	- TLB Error
	- Bus Error
	- Micro-architectural Error
	All other values are reserved

Yet, there was no information about how this would be encoded.

Spec 2.9A errata corrected it by defining:

	- Bit 1 - Cache Error
	- Bit 2 - TLB Error
	- Bit 3 - Bus Error
	- Bit 4 - Micro-architectural Error
	All other values are reserved

That actually aligns with the values already defined on older
versions at N.2.4.1. Generic Processor Error Section.

Spec 2.10 also preserve the same encoding as 2.9A.

Adjust CPER and GHES handling code for both generic and ARM
processors to properly handle UEFI 2.9A and 2.10 encoding.

Link: https://uefi.org/specs/UEFI/2.10/Apx_N_Common_Platform_Error_Record.html#arm-processor-error-information
Signed-off-by: Mauro Carvalho Chehab 
Reviewed-by: Jonathan Cameron 
Acked-by: Borislav Petkov (AMD) 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Sasha Levin

efi/cper: Adjust infopfx size to accept an extra space

2026-01-19T12:11:39+00:00

[ Upstream commit 8ad2c72e21efb3dc76c5b14089fa7984cdd87898 ]

Compiling with W=1 with werror enabled produces an error:

drivers/firmware/efi/cper-arm.c: In function ‘cper_print_proc_arm’:
drivers/firmware/efi/cper-arm.c:298:64: error: ‘snprintf’ output may be truncated before the last format character [-Werror=format-truncation=]
  298 |                         snprintf(infopfx, sizeof(infopfx), "%s ", newpfx);
      |                                                                ^
drivers/firmware/efi/cper-arm.c:298:25: note: ‘snprintf’ output between 2 and 65 bytes into a destination of size 64
  298 |                         snprintf(infopfx, sizeof(infopfx), "%s ", newpfx);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

As the logic there adds an space at the end of infopx buffer.
Add an extra space to avoid such warning.

Signed-off-by: Mauro Carvalho Chehab 
Reviewed-by: Jonathan Cameron 
Acked-by: Borislav Petkov (AMD) 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Sasha Levin

efi/cper: Add a new helper function to print bitmasks

2026-01-19T12:11:39+00:00

[ Upstream commit a976d790f49499ccaa0f991788ad8ebf92e7fd5c ]

Add a helper function to print a string with names associated
to each bit field.

A typical example is:

	const char * const bits[] = {
		"bit 3 name",
		"bit 4 name",
		"bit 5 name",
	};
	char str[120];
        unsigned int bitmask = BIT(3) | BIT(5);

	#define MASK  GENMASK(5,3)

	cper_bits_to_str(str, sizeof(str), FIELD_GET(MASK, bitmask),
			 bits, ARRAY_SIZE(bits));

The above code fills string "str" with "bit 3 name|bit 5 name".

Reviewed-by: Jonathan Cameron 
Signed-off-by: Mauro Carvalho Chehab 
Acked-by: Borislav Petkov (AMD) 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Sasha Levin