diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index c76ef1d701c9..278d645d108a 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -455,6 +455,7 @@ static int spurious_fault(unsigned long address, pud_t *pud; pmd_t *pmd; pte_t *pte; + int ret; /* Reserved-bit violation or user access to kernel space? */ if (error_code & (PF_USER | PF_RSVD)) @@ -482,7 +483,17 @@ static int spurious_fault(unsigned long address, if (!pte_present(*pte)) return 0; - return spurious_fault_check(error_code, pte); + ret = spurious_fault_check(error_code, pte); + if (!ret) + return 0; + + /* + * Make sure we have permissions in PMD + * If not, then there's a bug in the page tables. + */ + ret = spurious_fault_check(error_code, (pte_t *) pmd); + WARN_ONCE(!ret, "PMD has incorrect permission bits\n"); + return ret; } /*