From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 464DDC3A5A9 for ; Wed, 4 Sep 2019 16:05:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0128D2070C for ; Wed, 4 Sep 2019 16:05:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567613113; bh=bP67rUnQuQQMO/vk4mRw7dPx0htZlKaooFSF+6uvFV8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0Kq857aegoA9DL5t9B0mzOE274Ud6z0yQVhMFF3MW2O+iv1BQvJmfjxIXiFCFMPbm sg4BHwK/kV1e+PY9YQyxX0am5u7M1ONB86SZA4mxXviEPUlfCtGzYbvvC5YedYOeFQ EbQ4jdZeDTL7fZKZqcgZfhqvHdUW5JyVvyFkoPWs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387528AbfIDQCz (ORCPT ); Wed, 4 Sep 2019 12:02:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:39090 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387508AbfIDQCx (ORCPT ); Wed, 4 Sep 2019 12:02:53 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7EDF52070C; Wed, 4 Sep 2019 16:02:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567612972; bh=bP67rUnQuQQMO/vk4mRw7dPx0htZlKaooFSF+6uvFV8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RH6fW2dWkPXC3riDhkk4SBT9/5EUYMUCrEdlGME8zry0pvBAARjXWPE6REIckFcHA t8MXaiGdVDoag6xpp+6no01Jcb6h9Bh/Y9vG4I+5kLYh1QDoMTGYJ2OTBIOGgl5wKE zbnAeBy4ZTtbaRPFG6VVzsMacuHhHFDGpWH6IcH8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: zhaoyang , Zhaoyang Huang , Russell King , Sasha Levin Subject: [PATCH AUTOSEL 4.9 21/27] ARM: 8901/1: add a criteria for pfn_valid of arm Date: Wed, 4 Sep 2019 12:02:14 -0400 Message-Id: <20190904160220.4545-21-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190904160220.4545-1-sashal@kernel.org> References: <20190904160220.4545-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: zhaoyang [ Upstream commit 5b3efa4f1479c91cb8361acef55f9c6662feba57 ] pfn_valid can be wrong when parsing a invalid pfn whose phys address exceeds BITS_PER_LONG as the MSB will be trimed when shifted. The issue originally arise from bellowing call stack, which corresponding to an access of the /proc/kpageflags from userspace with a invalid pfn parameter and leads to kernel panic. [46886.723249] c7 [] (stable_page_flags) from [] [46886.723264] c7 [] (kpageflags_read) from [] [46886.723280] c7 [] (proc_reg_read) from [] [46886.723290] c7 [] (__vfs_read) from [] [46886.723301] c7 [] (vfs_read) from [] [46886.723315] c7 [] (SyS_pread64) from [] (ret_fast_syscall+0x0/0x28) Signed-off-by: Zhaoyang Huang Signed-off-by: Russell King Signed-off-by: Sasha Levin --- arch/arm/mm/init.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 4fb1474141a61..0fe4a7025e467 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -192,6 +192,11 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max_low, #ifdef CONFIG_HAVE_ARCH_PFN_VALID int pfn_valid(unsigned long pfn) { + phys_addr_t addr = __pfn_to_phys(pfn); + + if (__phys_to_pfn(addr) != pfn) + return 0; + return memblock_is_map_memory(__pfn_to_phys(pfn)); } EXPORT_SYMBOL(pfn_valid); -- 2.20.1