From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f174.google.com (mail-ie0-f174.google.com [209.85.223.174]) by kanga.kvack.org (Postfix) with ESMTP id 9B0F96B0138 for ; Tue, 11 Nov 2014 20:38:40 -0500 (EST) Received: by mail-ie0-f174.google.com with SMTP id x19so12649919ier.33 for ; Tue, 11 Nov 2014 17:38:40 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id vb8si28605083icb.68.2014.11.11.17.38.39 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 11 Nov 2014 17:38:39 -0800 (PST) From: Greg Kroah-Hartman Subject: [PATCH 3.14 035/203] x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE Date: Wed, 12 Nov 2014 10:15:05 +0900 Message-Id: <20141112011544.326707411@linuxfoundation.org> In-Reply-To: <20141112011542.686743533@linuxfoundation.org> References: <20141112011542.686743533@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dexuan Cui , "K. Y. Srinivasan" , Haiyang Zhang , linux-mm@kvack.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, dave.hansen@intel.com, riel@redhat.com, Thomas Gleixner 3.14-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 Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1414580017-27444-1-git-send-email-decui@microsoft.com Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/pageattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -405,7 +405,7 @@ phys_addr_t slow_virt_to_phys(void *__vi 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); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org