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=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 E4D82C352A9 for ; Sun, 29 Sep 2019 17:34:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C10F621A4C for ; Sun, 29 Sep 2019 17:34:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569778456; bh=w2whw1Hr/775putsFnagWM9RGPe7vXYrduAUtGNqhKA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SLPMLG+9GPTfYxas1MfkX5LNviBf54p9doLQdNnAQu38uAv5m2jbddQF42JZGiSLC 7fjbg0t9NZSPMVOogX1bL67xJRgIySY85rO0BeBlaLQPFdFJbvUHefodkB2Vh7Jr2v qdembJnLKA6dLML09mduD817feyHbEc+8FJVg5tw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729527AbfI2ReP (ORCPT ); Sun, 29 Sep 2019 13:34:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:45904 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730323AbfI2ReN (ORCPT ); Sun, 29 Sep 2019 13:34:13 -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 C17B921906; Sun, 29 Sep 2019 17:34:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569778452; bh=w2whw1Hr/775putsFnagWM9RGPe7vXYrduAUtGNqhKA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q5/7G4ooWzq9i8y9Yb6FhOF1luL3xMGdfNOj3ylyUBBJ2zNGIK23iBJU4j2GZbBQz aa1Ccww2wfzkeC4YAnOLWHQJQhtUkNTrjz7dZkU+ed7nrWG5bsqkcylB0LVPF51vdP EIBHI75TsB+MxBsTENFYFDvScxH6/2m8RIa3mmPg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alexandre Ghiti , Kees Cook , Paul Burton , Luis Chamberlain , Albert Ou , Alexander Viro , Catalin Marinas , Christoph Hellwig , Christoph Hellwig , James Hogan , Palmer Dabbelt , Ralf Baechle , Russell King , Will Deacon , Andrew Morton , Linus Torvalds , Sasha Levin , linux-mips@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 40/42] mips: properly account for stack randomization and stack guard gap Date: Sun, 29 Sep 2019 13:32:39 -0400 Message-Id: <20190929173244.8918-40-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190929173244.8918-1-sashal@kernel.org> References: <20190929173244.8918-1-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: Alexandre Ghiti [ Upstream commit b1f61b5bde3a1f50392c97b4c8513d1b8efb1cf2 ] This commit takes care of stack randomization and stack guard gap when computing mmap base address and checks if the task asked for randomization. This fixes the problem uncovered and not fixed for arm here: https://lkml.kernel.org/r/20170622200033.25714-1-riel@redhat.com Link: http://lkml.kernel.org/r/20190730055113.23635-10-alex@ghiti.fr Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Acked-by: Paul Burton Reviewed-by: Luis Chamberlain Cc: Albert Ou Cc: Alexander Viro Cc: Catalin Marinas Cc: Christoph Hellwig Cc: Christoph Hellwig Cc: James Hogan Cc: Palmer Dabbelt Cc: Ralf Baechle Cc: Russell King Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- arch/mips/mm/mmap.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index d79f2b4323187..f5c778113384b 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -21,8 +21,9 @@ unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ EXPORT_SYMBOL(shm_align_mask); /* gap between mmap and stack */ -#define MIN_GAP (128*1024*1024UL) -#define MAX_GAP ((TASK_SIZE)/6*5) +#define MIN_GAP (128*1024*1024UL) +#define MAX_GAP ((TASK_SIZE)/6*5) +#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) static int mmap_is_legacy(struct rlimit *rlim_stack) { @@ -38,6 +39,15 @@ static int mmap_is_legacy(struct rlimit *rlim_stack) static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) { unsigned long gap = rlim_stack->rlim_cur; + unsigned long pad = stack_guard_gap; + + /* Account for stack randomization if necessary */ + if (current->flags & PF_RANDOMIZE) + pad += (STACK_RND_MASK << PAGE_SHIFT); + + /* Values close to RLIM_INFINITY can overflow. */ + if (gap + pad > gap) + gap += pad; if (gap < MIN_GAP) gap = MIN_GAP; -- 2.20.1