efi/x86: Mark kernel rodata non-executable for mixed mode

When remapping the kernel rodata section RO in the EFI pagetables, the
protection flags that were used for the text section are being reused,
but the rodata section should not be marked executable.

Cc: <stable@vger.kernel.org>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200717194526.3452089-1-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 413583f904a695365e460502ff8f9b76ca844aa9..6af4da1149bacfe58b8f45b9c9d8ef60da261abc 100644 (file)
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -259,6 +259,8 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
        npages = (__end_rodata - __start_rodata) >> PAGE_SHIFT;
        rodata = __pa(__start_rodata);
        pfn = rodata >> PAGE_SHIFT;
+
+       pf = _PAGE_NX | _PAGE_ENC;
        if (kernel_map_pages_in_pgd(pgd, pfn, rodata, npages, pf)) {
                pr_err("Failed to map kernel rodata 1:1\n");
                return 1;