From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934051AbcIUWZR (ORCPT ); Wed, 21 Sep 2016 18:25:17 -0400 Received: from mail-yw0-f170.google.com ([209.85.161.170]:35102 "EHLO mail-yw0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933101AbcIUWZP (ORCPT ); Wed, 21 Sep 2016 18:25:15 -0400 From: Laura Abbott To: Catalin Marinas , Will Deacon , Ard Biesheuvel , Mark Rutland Cc: Laura Abbott , Kees Cook , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCHv2] arm64: Correctly bounds check virt_addr_valid Date: Wed, 21 Sep 2016 15:25:04 -0700 Message-Id: <1474496704-30541-1-git-send-email-labbott@redhat.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org virt_addr_valid is supposed to return true if and only if virt_to_page returns a valid page structure. The current macro does math on whatever address is given and passes that to pfn_valid to verify. vmalloc and module addresses can happen to generate a pfn that 'happens' to be valid. Fix this by only performing the pfn_valid check on addresses that have the potential to be valid. Acked-by: Mark Rutland Signed-off-by: Laura Abbott --- v2: Properly parenthesize macro arguments. Re-factor to common macro. Also in case it wasn't clear, there's no need to try and squeeze this into 4.8. Hardened usercopy should have all the checks, this is just for full correctness. --- arch/arm64/include/asm/memory.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 31b7322..ba62df8 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -214,7 +214,7 @@ static inline void *phys_to_virt(phys_addr_t x) #ifndef CONFIG_SPARSEMEM_VMEMMAP #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT) -#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) +#define _virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) #else #define __virt_to_pgoff(kaddr) (((u64)(kaddr) & ~PAGE_OFFSET) / PAGE_SIZE * sizeof(struct page)) #define __page_to_voff(kaddr) (((u64)(page) & ~VMEMMAP_START) * PAGE_SIZE / sizeof(struct page)) @@ -222,11 +222,15 @@ static inline void *phys_to_virt(phys_addr_t x) #define page_to_virt(page) ((void *)((__page_to_voff(page)) | PAGE_OFFSET)) #define virt_to_page(vaddr) ((struct page *)((__virt_to_pgoff(vaddr)) | VMEMMAP_START)) -#define virt_addr_valid(kaddr) pfn_valid((((u64)(kaddr) & ~PAGE_OFFSET) \ +#define _virt_addr_valid(kaddr) pfn_valid((((u64)(kaddr) & ~PAGE_OFFSET) \ + PHYS_OFFSET) >> PAGE_SHIFT) #endif #endif +#define _virt_addr_is_linear(kaddr) (((u64)(kaddr)) >= PAGE_OFFSET) +#define virt_addr_valid(kaddr) (_virt_addr_is_linear(kaddr) && \ + _virt_addr_valid(kaddr)) + #include #endif -- 2.7.4