From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 107/128] mm: enforce that vmap can't map pages executable Date: Mon, 01 Jun 2020 21:51:32 -0700 Message-ID: <20200602045132.CXcMOHwpv%akpm@linux-foundation.org> References: <20200601214457.919c35648e96a2b46b573fe1@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:44400 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725890AbgFBEvf (ORCPT ); Tue, 2 Jun 2020 00:51:35 -0400 In-Reply-To: <20200601214457.919c35648e96a2b46b573fe1@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: airlied@linux.ie, akpm@linux-foundation.org, benh@kernel.crashing.org, borntraeger@de.ibm.com, catalin.marinas@arm.com, christophe.leroy@c-s.fr, daniel.vetter@ffwll.ch, daniel@ffwll.ch, gor@linux.ibm.com, gregkh@linuxfoundation.org, haiyangz@microsoft.com, hannes@cmpxchg.org, hch@lst.de, heiko.carstens@de.ibm.com, kys@microsoft.com, labbott@redhat.com, linux-mm@kvack.org, mark.rutland@arm.com, mikelley@microsoft.com, minchan@kernel.org, mm-commits@vger.kernel.org, ngupta@vflare.org, paulus@ozlabs.org, peterz@infradead.org, robin.murphy@arm.com, sakari.ailus@linux.intel.com, sthemmin@microsoft.com, sumit.semwal@linaro.org, torvalds@linux-foundation.org, wei.liu@kernel.org, will@kernel.org, xiang@kernel.org From: Christoph Hellwig Subject: mm: enforce that vmap can't map pages executable To help enforcing the W^X protection don't allow remapping existing pages as executable. x86 bits from Peter Zijlstra, arm64 bits from Mark Rutland. Link: http://lkml.kernel.org/r/20200414131348.444715-20-hch@lst.de Signed-off-by: Christoph Hellwig Acked-by: Peter Zijlstra (Intel) Cc: Mark Rutland . Cc: Christian Borntraeger Cc: Christophe Leroy Cc: Daniel Vetter Cc: Daniel Vetter Cc: David Airlie Cc: Gao Xiang Cc: Greg Kroah-Hartman Cc: Haiyang Zhang Cc: Johannes Weiner Cc: "K. Y. Srinivasan" Cc: Laura Abbott Cc: Michael Kelley Cc: Minchan Kim Cc: Nitin Gupta Cc: Robin Murphy Cc: Sakari Ailus Cc: Stephen Hemminger Cc: Sumit Semwal Cc: Wei Liu Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: Heiko Carstens Cc: Paul Mackerras Cc: Vasily Gorbik Cc: Will Deacon Signed-off-by: Andrew Morton --- arch/arm64/include/asm/pgtable.h | 3 +++ arch/x86/include/asm/pgtable_types.h | 6 ++++++ include/asm-generic/pgtable.h | 4 ++++ mm/vmalloc.c | 2 +- 4 files changed, 14 insertions(+), 1 deletion(-) --- a/arch/arm64/include/asm/pgtable.h~mm-enforce-that-vmap-cant-map-pages-executable +++ a/arch/arm64/include/asm/pgtable.h @@ -407,6 +407,9 @@ static inline pmd_t pmd_mkdevmap(pmd_t p #define __pgprot_modify(prot,mask,bits) \ __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) +#define pgprot_nx(prot) \ + __pgprot_modify(prot, 0, PTE_PXN) + /* * Mark the prot value as uncacheable and unbufferable. */ --- a/arch/x86/include/asm/pgtable_types.h~mm-enforce-that-vmap-cant-map-pages-executable +++ a/arch/x86/include/asm/pgtable_types.h @@ -282,6 +282,12 @@ typedef struct pgprot { pgprotval_t pgpr typedef struct { pgdval_t pgd; } pgd_t; +static inline pgprot_t pgprot_nx(pgprot_t prot) +{ + return __pgprot(pgprot_val(prot) | _PAGE_NX); +} +#define pgprot_nx pgprot_nx + #ifdef CONFIG_X86_PAE /* --- a/include/asm-generic/pgtable.h~mm-enforce-that-vmap-cant-map-pages-executable +++ a/include/asm-generic/pgtable.h @@ -491,6 +491,10 @@ static inline int arch_unmap_one(struct #define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address) #endif +#ifndef pgprot_nx +#define pgprot_nx(prot) (prot) +#endif + #ifndef pgprot_noncached #define pgprot_noncached(prot) (prot) #endif --- a/mm/vmalloc.c~mm-enforce-that-vmap-cant-map-pages-executable +++ a/mm/vmalloc.c @@ -2391,7 +2391,7 @@ void *vmap(struct page **pages, unsigned if (!area) return NULL; - if (map_kernel_range((unsigned long)area->addr, size, prot, + if (map_kernel_range((unsigned long)area->addr, size, pgprot_nx(prot), pages) < 0) { vunmap(area->addr); return NULL; _