Seen during KPTI initialization:
CFI failure at create_kpti_ng_temp_pgd+0x124/0xce8 (target: kpti_ng_pgd_alloc+0x0/0x14; expected type: 0xd61b88b6)
The call site is alloc_init_pud() at arch/arm64/mm/mmu.c:
pud_phys = pgtable_alloc(TABLE_PUD);
alloc_init_pud() has the prototype:
static void alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end,
phys_addr_t phys, pgprot_t prot,
phys_addr_t (*pgtable_alloc)(enum pgtable_type),
int flags)
where the pgtable_alloc() prototype is declared.
The target (kpti_ng_pgd_alloc) is used in arch/arm64/kernel/cpufeature.c:
create_kpti_ng_temp_pgd(kpti_ng_temp_pgd, __pa(alloc), KPTI_NG_TEMP_VA,
PAGE_SIZE, PAGE_KERNEL, kpti_ng_pgd_alloc, 0);
which is an alias for __create_pgd_mapping_locked() with prototype:
extern __alias(__create_pgd_mapping_locked)
void create_kpti_ng_temp_pgd(pgd_t *pgdir, phys_addr_t phys,
unsigned long virt,
phys_addr_t size, pgprot_t prot,
phys_addr_t (*pgtable_alloc)(enum pgtable_type),
int flags);
__create_pgd_mapping_locked() passes the function pointer down:
__create_pgd_mapping_locked() -> alloc_init_p4d() -> alloc_init_pud()
But the target function (kpti_ng_pgd_alloc) has the wrong signature:
static phys_addr_t __init kpti_ng_pgd_alloc(int shift);
The "int" should be "enum pgtable_type".
To make "enum pgtable_type" available to cpufeature.c, move
enum pgtable_type definition from arch/arm64/mm/mmu.c to
arch/arm64/include/asm/mmu.h.
Adjust kpti_ng_pgd_alloc to use "enum pgtable_type" instead of "int".
The function behavior remains identical (parameter is unused).
Fixes: c64f46ee13 ("arm64: mm: use enum to identify pgtable level instead of *_SHIFT")
Cc: <stable@vger.kernel.org> # 6.16.x
Signed-off-by: Kees Cook <kees@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250829190721.it.373-kees@kernel.org
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
ceca927c86