Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754560AbaKKLLk (ORCPT ); Tue, 11 Nov 2014 06:11:40 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:57881 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753040AbaKKLL3 (ORCPT ); Tue, 11 Nov 2014 06:11:29 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Dexuan Cui , "K. Y. Srinivasan" , Haiyang Zhang , gregkh@linuxfoundation.org, linux-mm@kvack.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, dave.hansen@intel.com, riel@redhat.com, Thomas Gleixner , Luis Henriques Subject: [PATCH 3.16.y-ckt 149/170] x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE Date: Tue, 11 Nov 2014 11:08:28 +0000 Message-Id: <1415704129-12709-150-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1415704129-12709-1-git-send-email-luis.henriques@canonical.com> References: <1415704129-12709-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Dexuan Cui commit d1cd1210834649ce1ca6bafe5ac25d2f40331343 upstream. pte_pfn() returns a PFN of long (32 bits in 32-PAE), so "long << PAGE_SHIFT" will overflow for PFNs above 4GB. Due to this issue, some Linux 32-PAE distros, running as guests on Hyper-V, with 5GB memory assigned, can't load the netvsc driver successfully and hence the synthetic network device can't work (we can use the kernel parameter mem=3000M to work around the issue). Cast pte_pfn() to phys_addr_t before shifting. Fixes: "commit d76565344512: x86, mm: Create slow_virt_to_phys()" Signed-off-by: Dexuan Cui Cc: K. Y. Srinivasan Cc: Haiyang Zhang Cc: gregkh@linuxfoundation.org Cc: linux-mm@kvack.org Cc: olaf@aepfle.de Cc: apw@canonical.com Cc: jasowang@redhat.com Cc: dave.hansen@intel.com Cc: riel@redhat.com Link: http://lkml.kernel.org/r/1414580017-27444-1-git-send-email-decui@microsoft.com Signed-off-by: Thomas Gleixner Signed-off-by: Luis Henriques --- arch/x86/mm/pageattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index ae242a7c11c7..36de293caf25 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -409,7 +409,7 @@ phys_addr_t slow_virt_to_phys(void *__virt_addr) psize = page_level_size(level); pmask = page_level_mask(level); offset = virt_addr & ~pmask; - phys_addr = pte_pfn(*pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; return (phys_addr | offset); } EXPORT_SYMBOL_GPL(slow_virt_to_phys); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/