This is a note to let you know that I've just added the patch titled
efi/libstub: Add limit argument to efi_random_alloc()
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
efi-libstub-add-limit-argument-to-efi_random_alloc.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable+bounces-25901-greg=kroah.com@xxxxxxxxxxxxxxx Mon Mar 4 12:21:00 2024
From: Ard Biesheuvel <ardb+git@xxxxxxxxxx>
Date: Mon, 4 Mar 2024 12:19:46 +0100
Subject: efi/libstub: Add limit argument to efi_random_alloc()
To: stable@xxxxxxxxxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx, Ard Biesheuvel <ardb@xxxxxxxxxx>, Borislav Petkov <bp@xxxxxxxxx>
Message-ID: <20240304111937.2556102-28-ardb+git@xxxxxxxxxx>
From: Ard Biesheuvel <ardb+git@xxxxxxxxxx>
From: Ard Biesheuvel <ardb@xxxxxxxxxx>
[ Commit bc5ddceff4c14494d83449ad45c985e6cd353fce upstream ]
x86 will need to limit the kernel memory allocation to the lowest 512
MiB of memory, to match the behavior of the existing bare metal KASLR
physical randomization logic. So in preparation for that, add a limit
parameter to efi_random_alloc() and wire it up.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230807162720.545787-22-ardb@xxxxxxxxxx
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/firmware/efi/libstub/arm64-stub.c | 2 +-
drivers/firmware/efi/libstub/efistub.h | 2 +-
drivers/firmware/efi/libstub/randomalloc.c | 10 ++++++----
3 files changed, 8 insertions(+), 6 deletions(-)
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -181,7 +181,7 @@ efi_status_t handle_kernel_image(unsigne
*/
status = efi_random_alloc(*reserve_size, min_kimg_align,
reserve_addr, phys_seed,
- EFI_LOADER_CODE);
+ EFI_LOADER_CODE, EFI_ALLOC_LIMIT);
if (status != EFI_SUCCESS)
efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
} else {
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -905,7 +905,7 @@ efi_status_t efi_get_random_bytes(unsign
efi_status_t efi_random_alloc(unsigned long size, unsigned long align,
unsigned long *addr, unsigned long random_seed,
- int memory_type);
+ int memory_type, unsigned long alloc_limit);
efi_status_t efi_random_get_seed(void);
--- a/drivers/firmware/efi/libstub/randomalloc.c
+++ b/drivers/firmware/efi/libstub/randomalloc.c
@@ -16,7 +16,8 @@
*/
static unsigned long get_entry_num_slots(efi_memory_desc_t *md,
unsigned long size,
- unsigned long align_shift)
+ unsigned long align_shift,
+ u64 alloc_limit)
{
unsigned long align = 1UL << align_shift;
u64 first_slot, last_slot, region_end;
@@ -29,7 +30,7 @@ static unsigned long get_entry_num_slots
return 0;
region_end = min(md->phys_addr + md->num_pages * EFI_PAGE_SIZE - 1,
- (u64)EFI_ALLOC_LIMIT);
+ alloc_limit);
if (region_end < size)
return 0;
@@ -54,7 +55,8 @@ efi_status_t efi_random_alloc(unsigned l
unsigned long align,
unsigned long *addr,
unsigned long random_seed,
- int memory_type)
+ int memory_type,
+ unsigned long alloc_limit)
{
unsigned long total_slots = 0, target_slot;
unsigned long total_mirrored_slots = 0;
@@ -76,7 +78,7 @@ efi_status_t efi_random_alloc(unsigned l
efi_memory_desc_t *md = (void *)map->map + map_offset;
unsigned long slots;
- slots = get_entry_num_slots(md, size, ilog2(align));
+ slots = get_entry_num_slots(md, size, ilog2(align), alloc_limit);
MD_NUM_SLOTS(md) = slots;
total_slots += slots;
if (md->attribute & EFI_MEMORY_MORE_RELIABLE)
Patches currently in stable-queue which might be from kroah.com@xxxxxxxxxxxxxxx are
queue-6.1/x86-decompressor-avoid-magic-offsets-for-efi-handover-entrypoint.patch
queue-6.1/x86-efistub-avoid-placing-the-kernel-below-load_physical_addr.patch
queue-6.1/x86-efistub-avoid-legacy-decompressor-when-doing-efi-boot.patch
queue-6.1/x86-efistub-perform-4-5-level-paging-switch-from-the-stub.patch
queue-6.1/x86-boot-rename-conflicting-boot_params-pointer-to-boot_params_ptr.patch
queue-6.1/x86-efistub-perform-snp-feature-test-while-running-in-the-firmware.patch
queue-6.1/x86-efistub-simplify-and-clean-up-handover-entry-code.patch
queue-6.1/efi-libstub-add-memory-attribute-protocol-definitions.patch
queue-6.1/efi-libstub-add-limit-argument-to-efi_random_alloc.patch
queue-6.1/efi-x86-fix-the-missing-kaslr_flag-bit-in-boot_params-hdr.loadflags.patch
queue-6.1/arm64-efi-limit-allocations-to-48-bit-addressable-physical-region.patch
queue-6.1/x86-efistub-prefer-efi-memory-attributes-protocol-over-dxe-services.patch
queue-6.1/efi-efivars-prevent-double-registration.patch
queue-6.1/x86-boot-efistub-assign-global-boot_params-variable.patch
queue-6.1/x86-efistub-clear-bss-in-efi-handover-protocol-entrypoint.patch
queue-6.1/x86-decompressor-factor-out-kernel-decompression-and-relocation.patch
queue-6.1/efi-x86-avoid-physical-kaslr-on-older-dell-systems.patch
