From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f52.google.com (mail-wg0-f52.google.com [74.125.82.52]) by kanga.kvack.org (Postfix) with ESMTP id 2560B6B00CD for ; Fri, 14 Nov 2014 07:26:29 -0500 (EST) Received: by mail-wg0-f52.google.com with SMTP id b13so19106072wgh.25 for ; Fri, 14 Nov 2014 04:26:28 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id ex3si49021965wjd.56.2014.11.14.04.26.27 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 14 Nov 2014 04:26:28 -0800 (PST) From: Jiri Slaby Subject: [patch added to the 3.12 stable tree] x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE Date: Fri, 14 Nov 2014 13:25:49 +0100 Message-Id: <1415967978-8989-51-git-send-email-jslaby@suse.cz> In-Reply-To: <1415967978-8989-1-git-send-email-jslaby@suse.cz> References: <1415967978-8989-1-git-send-email-jslaby@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: stable@vger.kernel.org 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 , Jiri Slaby From: Dexuan Cui This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== 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: Jiri Slaby --- 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 bb32480c2d71..aabdf762f592 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -389,7 +389,7 @@ 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); -- 2.1.3 -- 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