From patchwork Thu Aug 8 06:17:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11083295 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A7C8F13AC for ; Thu, 8 Aug 2019 06:28:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 924A328657 for ; Thu, 8 Aug 2019 06:28:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 81B1E28A3D; Thu, 8 Aug 2019 06:28:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 21D6128657 for ; Thu, 8 Aug 2019 06:28:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5eeyRprc8x+6qnc9dG+1CrSczGVOdKUkR1UGzPVcKyA=; b=Cf7zgv6PcPrdiI 2olIWh2ni9kpeKZeaRKRdlHp7LpEEqf89XuyOYZ2+ZEwc2bRCNB2TYqo3bqI9bPPoG5IZirXxRrh1 c2QrgEBLFDOEEL2xIhCKDPhmCrlQPyjEzZmdQYL1UUwdqijR/xb12FhXvborEGAtI+r9JFPXSmDY2 XTVi8A+I/9zW5P/fI/yTDULnhpGOF3LKyQQ1tA2uIzoeHTF98KERa5GIK72QmSWFG1fgwfWEmLOoP 1O/zZoKYamzeFkpn7ypPWeHbvHogY3Vv1xrvWetWcPQRdM/M7NZDe2/2lDDHEH6YOy8XePUJ/fP+v 6sAv9UOzIB05tmR1ZdLw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hvbuU-0001lL-Do; Thu, 08 Aug 2019 06:28:26 +0000 Received: from relay11.mail.gandi.net ([217.70.178.231]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hvbu1-0001FQ-Ru; Thu, 08 Aug 2019 06:27:59 +0000 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay11.mail.gandi.net (Postfix) with ESMTPSA id D6A23100005; Thu, 8 Aug 2019 06:27:51 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Subject: [PATCH v6 09/14] mips: Properly account for stack randomization and stack guard gap Date: Thu, 8 Aug 2019 02:17:51 -0400 Message-Id: <20190808061756.19712-10-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190808061756.19712-1-alex@ghiti.fr> References: <20190808061756.19712-1-alex@ghiti.fr> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190807_232758_084987_C04A9562 X-CRM114-Status: GOOD ( 10.67 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Albert Ou , Kees Cook , Alexandre Ghiti , linux-mm@kvack.org, Catalin Marinas , Palmer Dabbelt , Will Deacon , Russell King , Ralf Baechle , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Luis Chamberlain , Paul Burton , Paul Walmsley , James Hogan , linux-riscv@lists.infradead.org, linux-mips@vger.kernel.org, Christoph Hellwig , linux-arm-kernel@lists.infradead.org, Alexander Viro Sender: "linux-riscv" Errors-To: linux-riscv-bounces+patchwork-linux-riscv=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Acked-by: Paul Burton Reviewed-by: Luis Chamberlain --- 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 d79f2b432318..f5c778113384 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;