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authorDave Hansen <dave.hansen@linux.intel.com>2018-04-20 15:20:28 -0700
committerThomas Gleixner <tglx@linutronix.de>2018-04-25 11:02:51 +0200
commit316d097c4cd4e7f2ef50c40cff2db266593c4ec4 (patch)
tree0cbc41b328c814ddbfb51d9eb8e265f2a9cdb0e6 /mm/mmap.c
parentb7c21bc56fbedf4a61b628c6b11e0d7048746cc1 (diff)
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x86/pti: Filter at vma->vm_page_prot population
commit ce9962bf7e22bb3891655c349faff618922d4a73 0day reported warnings at boot on 32-bit systems without NX support: attempted to set unsupported pgprot: 8000000000000025 bits: 8000000000000000 supported: 7fffffffffffffff WARNING: CPU: 0 PID: 1 at arch/x86/include/asm/pgtable.h:540 handle_mm_fault+0xfc1/0xfe0: check_pgprot at arch/x86/include/asm/pgtable.h:535 (inlined by) pfn_pte at arch/x86/include/asm/pgtable.h:549 (inlined by) do_anonymous_page at mm/memory.c:3169 (inlined by) handle_pte_fault at mm/memory.c:3961 (inlined by) __handle_mm_fault at mm/memory.c:4087 (inlined by) handle_mm_fault at mm/memory.c:4124 The problem is that due to the recent commit which removed auto-massaging of page protections, filtering page permissions at PTE creation time is not longer done, so vma->vm_page_prot is passed unfiltered to PTE creation. Filter the page protections before they are installed in vma->vm_page_prot. Fixes: fb43d6cb91 ("x86/mm: Do not auto-massage page protections") Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Nadav Amit <namit@vmware.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Link: https://lkml.kernel.org/r/20180420222028.99D72858@viggo.jf.intel.com
Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 188f195883b9..9d5968d1e8e3 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -100,11 +100,20 @@ pgprot_t protection_map[16] __ro_after_init = {
__S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
};
+#ifndef CONFIG_ARCH_HAS_FILTER_PGPROT
+static inline pgprot_t arch_filter_pgprot(pgprot_t prot)
+{
+ return prot;
+}
+#endif
+
pgprot_t vm_get_page_prot(unsigned long vm_flags)
{
- return __pgprot(pgprot_val(protection_map[vm_flags &
+ pgprot_t ret = __pgprot(pgprot_val(protection_map[vm_flags &
(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
pgprot_val(arch_vm_get_page_prot(vm_flags)));
+
+ return arch_filter_pgprot(ret);
}
EXPORT_SYMBOL(vm_get_page_prot);