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=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 A1BDEECDE44 for ; Sun, 4 Nov 2018 13:53:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5ED932086C for ; Sun, 4 Nov 2018 13:53:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="2FGiXKmS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5ED932086C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731231AbeKDXIj (ORCPT ); Sun, 4 Nov 2018 18:08:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:47494 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731192AbeKDXIh (ORCPT ); Sun, 4 Nov 2018 18:08:37 -0500 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 C9FD020869; Sun, 4 Nov 2018 13:53:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541339613; bh=9u+KewjeAQMDyqLOeMJLYOrE6sY7eecZ21LFTOBiRm0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2FGiXKmSD2OxrdfsN95TmC4Zb9OYyu32tXEWAsi+fmKL2R3jtbuhB1rVldI3k4p5X SbYA2mqze1TKjh3ad1Th0FOYJBR9NWqO81TuNxJmE8iwX0/9/m6wPeEzqQ6CKfCz9D VUZUl3v++jk5GZb1OryJRi4E2Y6+DHiYB7YGLjD4= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Nicholas Piggin , Michael Ellerman , Sasha Levin Subject: [PATCH AUTOSEL 4.14 06/30] powerpc/64/module: REL32 relocation range check Date: Sun, 4 Nov 2018 08:53:01 -0500 Message-Id: <20181104135325.88524-6-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181104135325.88524-1-sashal@kernel.org> References: <20181104135325.88524-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicholas Piggin [ Upstream commit b851ba02a6f3075f0f99c60c4bc30a4af80cf428 ] The recent module relocation overflow crash demonstrated that we have no range checking on REL32 relative relocations. This patch implements a basic check, the same kernel that previously oopsed and rebooted now continues with some of these errors when loading the module: module_64: x_tables: REL32 527703503449812 out of range! Possibly other relocations (ADDR32, REL16, TOC16, etc.) should also have overflow checks. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin --- arch/powerpc/kernel/module_64.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 2a1b1273a312..4d8f6291b766 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -656,7 +656,14 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, case R_PPC64_REL32: /* 32 bits relative (used by relative exception tables) */ - *(u32 *)location = value - (unsigned long)location; + /* Convert value to relative */ + value -= (unsigned long)location; + if (value + 0x80000000 > 0xffffffff) { + pr_err("%s: REL32 %li out of range!\n", + me->name, (long int)value); + return -ENOEXEC; + } + *(u32 *)location = value; break; case R_PPC64_TOCSAVE: -- 2.17.1