x86/mpx: Fix off-by-one comparison with nr_registers

[firefly-linux-kernel-4.4.55.git] / arch / x86 / mm / pageattr.c

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index a3137a4feed15ed0d58189411e4e1ae2d9236e8a..db20ee9a413a0be6bfc735a94ade8cc1b50b82f8 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -33,7 +33,7 @@ struct cpa_data {
        pgd_t           *pgd;
        pgprot_t        mask_set;
        pgprot_t        mask_clr;
-       int             numpages;
+       unsigned long   numpages;
        int             flags;
        unsigned long   pfn;
        unsigned        force_split : 1;
@@ -1345,7 +1345,7 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
                 * CPA operation. Either a large page has been
                 * preserved or a single page update happened.
                 */
-               BUG_ON(cpa->numpages > numpages);
+               BUG_ON(cpa->numpages > numpages || !cpa->numpages);
                numpages -= cpa->numpages;
                if (cpa->flags & (CPA_PAGES_ARRAY | CPA_ARRAY))
                        cpa->curpage++;