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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 30D40C433E0 for ; Tue, 23 Jun 2020 17:36:36 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 00DD5207FF for ; Tue, 23 Jun 2020 17:36:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Xr09smX7"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="x4+C37qg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 00DD5207FF 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-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.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=uco3X07Li++J//rTlQ33vQLAG2hD0cXtzG4z550+sd0=; b=Xr09smX7rUxUsM14rfag4BJI2 MegBuygckGqdscHew2Kw8wOSvQViES+NmrzyC5BleK8NGRD1AqyA26pLi5KFCs6Wdj/n5jH8s+f2a 8J++j/wMpVd56WkyJqsqa4byirEZ5Z91gPXT+m8qpkrOp2QwaB76BORIAF530QQsnQ9McbNECPUpY 523RJ8SjWz5JaRBHaP2rWWUw+WJ7iaAXmqxPwRZCKEkDL6gdmcTUHN8lPq6Cm/5TAbUrDMivmrG2q ntYWCyXzyV9YwbWybPcwXx6ZV1g3MTndgaNqwK+V4/Bs5NkLvRFVfCQSCX01KCdi/PzKPLW6ziPeO HTxYauNYw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jnmqV-0003gY-Qf; Tue, 23 Jun 2020 17:36:31 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jnmqU-0003fj-1C for linux-riscv@lists.infradead.org; Tue, 23 Jun 2020 17:36:30 +0000 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 A2CDE2078A; Tue, 23 Jun 2020 17:36:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592933789; bh=KGTxbpDBwea5FTUqlV3d9WT6LzTHKFm5813Edct4Qfg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=x4+C37qg5AJZz0BDfSqX/2KZed2zZQ9cGwwn3WvQbNwlLjilXx0i9rtrhIBLuSPZi Wmmr842du+JOGfcxdPLdmfKMLOw5LI/87mNlHgqs5U7LOSbWqT1ZjAiLHLdeidRbub J6wim6hho0E2ssW93FEboDtd69ktFsOGNFUtBmJw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 24/24] RISC-V: Don't allow write+exec only page mapping request in mmap Date: Tue, 23 Jun 2020 13:35:59 -0400 Message-Id: <20200623173559.1355728-24-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200623173559.1355728-1-sashal@kernel.org> References: <20200623173559.1355728-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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: Sasha Levin , Yash Shah , Palmer Dabbelt , linux-riscv@lists.infradead.org, David Abdurachmanov Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Yash Shah [ Upstream commit e0d17c842c0f824fd4df9f4688709fc6907201e1 ] As per the table 4.4 of version "20190608-Priv-MSU-Ratified" of the RISC-V instruction set manual[0], the PTE permission bit combination of "write+exec only" is reserved for future use. Hence, don't allow such mapping request in mmap call. An issue is been reported by David Abdurachmanov, that while running stress-ng with "sysbadaddr" argument, RCU stalls are observed on RISC-V specific kernel. This issue arises when the stress-sysbadaddr request for pages with "write+exec only" permission bits and then passes the address obtain from this mmap call to various system call. For the riscv kernel, the mmap call should fail for this particular combination of permission bits since it's not valid. [0]: http://dabbelt.com/~palmer/keep/riscv-isa-manual/riscv-privileged-20190608-1.pdf Signed-off-by: Yash Shah Reported-by: David Abdurachmanov [Palmer: Refer to the latest ISA specification at the only link I could find, and update the terminology.] Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- arch/riscv/kernel/sys_riscv.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index f3619f59d85cc..12f8a7fce78b1 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -8,6 +8,7 @@ #include #include #include +#include static long riscv_sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, @@ -16,6 +17,11 @@ static long riscv_sys_mmap(unsigned long addr, unsigned long len, { if (unlikely(offset & (~PAGE_MASK >> page_shift_offset))) return -EINVAL; + + if ((prot & PROT_WRITE) && (prot & PROT_EXEC)) + if (unlikely(!(prot & PROT_READ))) + return -EINVAL; + return ksys_mmap_pgoff(addr, len, prot, flags, fd, offset >> (PAGE_SHIFT - page_shift_offset)); } -- 2.25.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv