x86/speculation/l1tf: Fix up pte->pfn conversion for PAE

Jan has noticed that pte_pfn and co. resp. pfn_pte are incorrect for
CONFIG_PAE because phys_addr_t is wider than unsigned long and so the
pte_val reps. shift left would get truncated. Fix this up by using proper
types.

Fixes: 6b28baca9b1f ("x86/speculation/l1tf: Protect PROT_NONE PTEs against speculation")
Reported-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
CVE-2018-3620
CVE-2018-3646

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index ec9e2d6211c7e01f19e927cbc67f888ee28a600c..8a5a0c79a1b19003a13487edb156a30f5563b877 100644 (file)
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -191,21 +191,21 @@ static inline u64 protnone_mask(u64 val);
 
 static inline unsigned long pte_pfn(pte_t pte)
 {
-       unsigned long pfn = pte_val(pte);
+       phys_addr_t pfn = pte_val(pte);
        pfn ^= protnone_mask(pfn);
        return (pfn & PTE_PFN_MASK) >> PAGE_SHIFT;
 }
 
 static inline unsigned long pmd_pfn(pmd_t pmd)
 {
-       unsigned long pfn = pmd_val(pmd);
+       phys_addr_t pfn = pmd_val(pmd);
        pfn ^= protnone_mask(pfn);
        return (pfn & pmd_pfn_mask(pmd)) >> PAGE_SHIFT;
 }
 
 static inline unsigned long pud_pfn(pud_t pud)
 {
-       unsigned long pfn = pud_val(pud);
+       phys_addr_t pfn = pud_val(pud);
        pfn ^= protnone_mask(pfn);
        return (pfn & pud_pfn_mask(pud)) >> PAGE_SHIFT;
 }
@@ -555,7 +555,7 @@ static inline pgprotval_t check_pgprot(pgprot_t pgprot)
 
 static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
 {
-       phys_addr_t pfn = page_nr << PAGE_SHIFT;
+       phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
        pfn ^= protnone_mask(pgprot_val(pgprot));
        pfn &= PTE_PFN_MASK;
        return __pte(pfn | check_pgprot(pgprot));
@@ -563,7 +563,7 @@ static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
 
 static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
 {
-       phys_addr_t pfn = page_nr << PAGE_SHIFT;
+       phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
        pfn ^= protnone_mask(pgprot_val(pgprot));
        pfn &= PHYSICAL_PMD_PAGE_MASK;
        return __pmd(pfn | check_pgprot(pgprot));
@@ -571,7 +571,7 @@ static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
 
 static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot)
 {
-       phys_addr_t pfn = page_nr << PAGE_SHIFT;
+       phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
        pfn ^= protnone_mask(pgprot_val(pgprot));
        pfn &= PHYSICAL_PUD_PAGE_MASK;
        return __pud(pfn | check_pgprot(pgprot));