6.1-stable review patch. If anyone has any objections, please let me know.
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From: Ard Biesheuvel ardb@kernel.org
commit 9cf42bca30e98a1c6c9e8abf876940a551eaa3d1 upstream.
The EFI spec is not very clear about which permissions are being given when allocating pages of a certain type. However, it is quite obvious that EFI_LOADER_CODE is more likely to permit execution than EFI_LOADER_DATA, which becomes relevant once we permit booting the kernel proper with the firmware's 1:1 mapping still active.
Ostensibly, recent systems such as the Surface Pro X grant executable permissions to EFI_LOADER_CODE regions but not EFI_LOADER_DATA regions.
Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/firmware/efi/libstub/alignedmem.c | 5 +++-- drivers/firmware/efi/libstub/arm64-stub.c | 6 ++++-- drivers/firmware/efi/libstub/efistub.h | 6 ++++-- drivers/firmware/efi/libstub/mem.c | 3 ++- drivers/firmware/efi/libstub/randomalloc.c | 5 +++-- 5 files changed, 16 insertions(+), 9 deletions(-)
--- a/drivers/firmware/efi/libstub/alignedmem.c +++ b/drivers/firmware/efi/libstub/alignedmem.c @@ -22,7 +22,8 @@ * Return: status code */ efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr, - unsigned long max, unsigned long align) + unsigned long max, unsigned long align, + int memory_type) { efi_physical_addr_t alloc_addr; efi_status_t status; @@ -36,7 +37,7 @@ efi_status_t efi_allocate_pages_aligned( slack = align / EFI_PAGE_SIZE - 1;
status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS, - EFI_LOADER_DATA, size / EFI_PAGE_SIZE + slack, + memory_type, size / EFI_PAGE_SIZE + slack, &alloc_addr); if (status != EFI_SUCCESS) return status; --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -180,7 +180,8 @@ efi_status_t handle_kernel_image(unsigne * locate the kernel at a randomized offset in physical memory. */ status = efi_random_alloc(*reserve_size, min_kimg_align, - reserve_addr, phys_seed); + reserve_addr, phys_seed, + EFI_LOADER_CODE); if (status != EFI_SUCCESS) efi_warn("efi_random_alloc() failed: 0x%lx\n", status); } else { @@ -201,7 +202,8 @@ efi_status_t handle_kernel_image(unsigne }
status = efi_allocate_pages_aligned(*reserve_size, reserve_addr, - ULONG_MAX, min_kimg_align); + ULONG_MAX, min_kimg_align, + EFI_LOADER_CODE);
if (status != EFI_SUCCESS) { efi_err("Failed to relocate kernel\n"); --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -880,7 +880,8 @@ void efi_get_virtmap(efi_memory_desc_t * efi_status_t efi_get_random_bytes(unsigned long size, u8 *out);
efi_status_t efi_random_alloc(unsigned long size, unsigned long align, - unsigned long *addr, unsigned long random_seed); + unsigned long *addr, unsigned long random_seed, + int memory_type);
efi_status_t efi_random_get_seed(void);
@@ -907,7 +908,8 @@ efi_status_t efi_allocate_pages(unsigned unsigned long max);
efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr, - unsigned long max, unsigned long align); + unsigned long max, unsigned long align, + int memory_type);
efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align, unsigned long *addr, unsigned long min); --- a/drivers/firmware/efi/libstub/mem.c +++ b/drivers/firmware/efi/libstub/mem.c @@ -91,7 +91,8 @@ efi_status_t efi_allocate_pages(unsigned
if (EFI_ALLOC_ALIGN > EFI_PAGE_SIZE) return efi_allocate_pages_aligned(size, addr, max, - EFI_ALLOC_ALIGN); + EFI_ALLOC_ALIGN, + EFI_LOADER_DATA);
alloc_addr = ALIGN_DOWN(max + 1, EFI_ALLOC_ALIGN) - 1; status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS, --- a/drivers/firmware/efi/libstub/randomalloc.c +++ b/drivers/firmware/efi/libstub/randomalloc.c @@ -53,7 +53,8 @@ static unsigned long get_entry_num_slots efi_status_t efi_random_alloc(unsigned long size, unsigned long align, unsigned long *addr, - unsigned long random_seed) + unsigned long random_seed, + int memory_type) { unsigned long total_slots = 0, target_slot; unsigned long total_mirrored_slots = 0; @@ -118,7 +119,7 @@ efi_status_t efi_random_alloc(unsigned l pages = size / EFI_PAGE_SIZE;
status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS, - EFI_LOADER_DATA, pages, &target); + memory_type, pages, &target); if (status == EFI_SUCCESS) *addr = target; break;