Commit c2fe61d8 authored by Arvind Sankar's avatar Arvind Sankar Committed by Ard Biesheuvel

efi/x86: Free efi_pgd with free_pages()

Commit

  d9e9a641 ("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

    06ace26f ("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: d9e9a641 ("x86/mm/pti: Allocate a separate user PGD")
Link: https://lore.kernel.org/r/20201110163919.1134431-1-nivedita@alum.mit.eduSigned-off-by: default avatarArvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent fe5186cf
...@@ -78,28 +78,30 @@ int __init efi_alloc_page_tables(void) ...@@ -78,28 +78,30 @@ int __init efi_alloc_page_tables(void)
gfp_mask = GFP_KERNEL | __GFP_ZERO; gfp_mask = GFP_KERNEL | __GFP_ZERO;
efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER); efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
if (!efi_pgd) if (!efi_pgd)
return -ENOMEM; goto fail;
pgd = efi_pgd + pgd_index(EFI_VA_END); pgd = efi_pgd + pgd_index(EFI_VA_END);
p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END); p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
if (!p4d) { if (!p4d)
free_page((unsigned long)efi_pgd); goto free_pgd;
return -ENOMEM;
}
pud = pud_alloc(&init_mm, p4d, EFI_VA_END); pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
if (!pud) { if (!pud)
if (pgtable_l5_enabled()) goto free_p4d;
free_page((unsigned long) pgd_page_vaddr(*pgd));
free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
return -ENOMEM;
}
efi_mm.pgd = efi_pgd; efi_mm.pgd = efi_pgd;
mm_init_cpumask(&efi_mm); mm_init_cpumask(&efi_mm);
init_new_context(NULL, &efi_mm); init_new_context(NULL, &efi_mm);
return 0; 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;
} }
/* /*
......
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