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efi/x86: Free efi_pgd with free_pages() 

[ Upstream commit c2fe61d8be ]

Commit

  d9e9a64180 ("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

    06ace26f4e ("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: d9e9a64180 ("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>
5.4-rM2-2.2.x-imx-squashed
Arvind Sankar 2020-11-10 11:39:19 -05:00 committed by Greg Kroah-Hartman
parent 95fafa1cb7
commit 9d1b5a8c72
1 changed files with 13 additions and 11 deletions
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24
arch/x86/platform/efi/efi_64.c
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@ -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;
}
/*