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 5ECCFC433DF for ; Tue, 23 Jun 2020 17:37:00 +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 2F8ED20781 for ; Tue, 23 Jun 2020 17:37:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="NJM6rmUu"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="EqCZPCTR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F8ED20781 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=lK6W4YvlYC9dr5sUbpVg13AyFLCapRSjL8a0MytjU24=; b=NJM6rmUudKq9Q8rnY+xi6gVE/ uGejllgCXTSuWWaZtZXZFvlPflMFLHn7jCgDlKyZrp+EloJvbxJbzy9NVYV60t02nIC55KGI9T2r/ ZQ6rEjiRtnYr9TKZUEH+f4lOfqnFI19xvSdWlxuain8tCyWhVAOyUxOT1br8yBn32R56f8EBVqdhy fkc7rBBlviUJqLg+CFind2J2lcbRv8/MQ/rWTn/B39k4z9FCLgPK3MXm7GxCW7JUOAyObp7tKWbEE pHzmenDBcGP6joGXB++j1czgr140JZIbctkcqc9pufNmtexjU5cumd+m2f77j9P/+FKYtuum3qRpc Zjp6GiKLg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jnmqt-0003sc-0g; Tue, 23 Jun 2020 17:36:55 +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 1jnmqn-0003pT-NU for linux-riscv@lists.infradead.org; Tue, 23 Jun 2020 17:36:51 +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 5823920781; Tue, 23 Jun 2020 17:36:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592933809; bh=lxhKP8mUk7NWPWZ5S591OwGbHEUQgWTP8rlI4jSLJjM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EqCZPCTRryv1ABTYlYT5b6aJU1NaotyixNt2+tFsjijKLIt0qLEsVu26Pi8mdRDhl Y4MMP24WQYw+Olm2oTIEphT6+3TWvtS5V6oKASTLK5/SPF0prguzlwNIzzb8c/dIWf dMUnRMXZD9CEP4vaHa5AATipAfzF6QwL1QzsN8qs= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 15/15] RISC-V: Don't allow write+exec only page mapping request in mmap Date: Tue, 23 Jun 2020 13:36:30 -0400 Message-Id: <20200623173630.1355971-15-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200623173630.1355971-1-sashal@kernel.org> References: <20200623173630.1355971-1-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 fb03a4482ad60..db44da32701f2 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -16,6 +16,7 @@ #include #include #include +#include static long riscv_sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, @@ -24,6 +25,11 @@ 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