From: Arvind Sankar nivedita@alum.mit.edu
[ Upstream commit c2fe61d8be491ff8188edaf22e838f819999146b ]
Commit
d9e9a6418065 ("x86/mm/pti: Allocate a separate user PGD")
changed the PGD allocation to allocate PGD_ALLOCATION_ORDER pages, so in the error path it should be freed using free_pages() rather than free_page().
Commit
06ace26f4e6f ("x86/efi: Free efi_pgd with free_pages()")
fixed one instance of this, but missed another.
Move the freeing out-of-line to avoid code duplication and fix this bug.
Fixes: d9e9a6418065 ("x86/mm/pti: Allocate a separate user PGD") Link: https://lore.kernel.org/r/20201110163919.1134431-1-nivedita@alum.mit.edu Signed-off-by: Arvind Sankar nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/platform/efi/efi_64.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index e39c930cfbd1e..5283978181103 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -217,28 +217,30 @@ int __init efi_alloc_page_tables(void) gfp_mask = GFP_KERNEL | __GFP_ZERO; efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER); if (!efi_pgd) - return -ENOMEM; + goto fail;
pgd = efi_pgd + pgd_index(EFI_VA_END); p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END); - if (!p4d) { - free_page((unsigned long)efi_pgd); - return -ENOMEM; - } + if (!p4d) + goto free_pgd;
pud = pud_alloc(&init_mm, p4d, EFI_VA_END); - if (!pud) { - if (pgtable_l5_enabled()) - free_page((unsigned long) pgd_page_vaddr(*pgd)); - free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER); - return -ENOMEM; - } + if (!pud) + goto free_p4d;
efi_mm.pgd = efi_pgd; mm_init_cpumask(&efi_mm); init_new_context(NULL, &efi_mm);
return 0; + +free_p4d: + if (pgtable_l5_enabled()) + free_page((unsigned long)pgd_page_vaddr(*pgd)); +free_pgd: + free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER); +fail: + return -ENOMEM; }
/*