From patchwork Thu Oct 10 08:36:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 11182965 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E2F6176 for ; Thu, 10 Oct 2019 08:52:25 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 9C6DD20B7C for ; Thu, 10 Oct 2019 08:52:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QYq0wKNs"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="H5m/ljzz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9C6DD20B7C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org 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=KtjXQ+XRIHUNMylfsuPEGlB+KVhrol4MkgRT2Eq6qs0=; b=QYq0wKNsXk6zQE EHmis25Sj65xLBPgg2NyHwt76ADCGM6PSc4ePrDE+eiAfETsHq769rPjQqxfdy4YhIpU++w/i0n3d HIJEj3rJ27epmbM1C2Rii2q2iqw5TpfdNkn610CoSk2lMU89LEKcQOpAxge2x/p0vmeRqQrkRXlr9 VbjZs+fBUGrGxzTJNH3qFW9e931e2Z02F/KqDtEJ8Y89oq2nP82CXPOB+WFWGyPreeUp+qwA9zCjP ZhHvPTMb8ayzfRiwLzu4zGcOqr9hX17fzHaOn1MqMqIdyCXzKz/DJM3AkShiZKZUz1ZeTnAXYJ61h 1G8oTIW/3RuI95vq8cMg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iIUBK-0000sj-NB; Thu, 10 Oct 2019 08:52:22 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iIU8j-000592-Ow for linux-arm-kernel@lists.infradead.org; Thu, 10 Oct 2019 08:49:43 +0000 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BEC562064A; Thu, 10 Oct 2019 08:49:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697381; bh=uJMfqKzJmIl0AHWLDzSnls3gFjyu1Z+VHOUsfZ8MtdI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H5m/ljzzYCiUWnQBq+oJ4e+HRidQZ2EjXhhy/8Vqx5dciuQ0jZfzf1nmWC9cYolNq OSjasseeR9Oyyzfd0FUz+gQW8pCLBp+iCsCYvpLq2h46PjvmzRgjHjfy+IytkMS4BO it7N9ZOMNUzYSeX4vBFvtHLjrVSZtQh6CHOxu9e8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 4.19 092/114] arm64: fix SSBS sanitization Date: Thu, 10 Oct 2019 10:36:39 +0200 Message-Id: <20191010083612.970579789@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191010083544.711104709@linuxfoundation.org> References: <20191010083544.711104709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191010_014941_882884_385460F3 X-CRM114-Status: GOOD ( 11.21 ) X-Spam-Score: -5.0 (-----) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-5.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [198.145.29.99 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Suzuki K Poulose , Greg Kroah-Hartman , Ard Biesheuvel , Will Deacon , stable@vger.kernel.org, Catalin Marinas Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Mark Rutland [ Upstream commit f54dada8274643e3ff4436df0ea124aeedc43cae ] In valid_user_regs() we treat SSBS as a RES0 bit, and consequently it is unexpectedly cleared when we restore a sigframe or fiddle with GPRs via ptrace. This patch fixes valid_user_regs() to account for this, updating the function to refer to the latest ARM ARM (ARM DDI 0487D.a). For AArch32 tasks, SSBS appears in bit 23 of SPSR_EL1, matching its position in the AArch32-native PSR format, and we don't need to translate it as we have to for DIT. There are no other bit assignments that we need to account for today. As the recent documentation describes the DIT bit, we can drop our comment regarding DIT. While removing SSBS from the RES0 masks, existing inconsistent whitespace is corrected. Fixes: d71be2b6c0e19180 ("arm64: cpufeature: Detect SSBS and advertise to userspace") Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Suzuki K Poulose Cc: Will Deacon Signed-off-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/ptrace.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1666,19 +1666,20 @@ void syscall_trace_exit(struct pt_regs * } /* - * SPSR_ELx bits which are always architecturally RES0 per ARM DDI 0487C.a - * We also take into account DIT (bit 24), which is not yet documented, and - * treat PAN and UAO as RES0 bits, as they are meaningless at EL0, and may be - * allocated an EL0 meaning in future. + * SPSR_ELx bits which are always architecturally RES0 per ARM DDI 0487D.a. + * We permit userspace to set SSBS (AArch64 bit 12, AArch32 bit 23) which is + * not described in ARM DDI 0487D.a. + * We treat PAN and UAO as RES0 bits, as they are meaningless at EL0, and may + * be allocated an EL0 meaning in future. * Userspace cannot use these until they have an architectural meaning. * Note that this follows the SPSR_ELx format, not the AArch32 PSR format. * We also reserve IL for the kernel; SS is handled dynamically. */ #define SPSR_EL1_AARCH64_RES0_BITS \ - (GENMASK_ULL(63,32) | GENMASK_ULL(27, 25) | GENMASK_ULL(23, 22) | \ - GENMASK_ULL(20, 10) | GENMASK_ULL(5, 5)) + (GENMASK_ULL(63, 32) | GENMASK_ULL(27, 25) | GENMASK_ULL(23, 22) | \ + GENMASK_ULL(20, 13) | GENMASK_ULL(11, 10) | GENMASK_ULL(5, 5)) #define SPSR_EL1_AARCH32_RES0_BITS \ - (GENMASK_ULL(63,32) | GENMASK_ULL(23, 22) | GENMASK_ULL(20,20)) + (GENMASK_ULL(63, 32) | GENMASK_ULL(22, 22) | GENMASK_ULL(20, 20)) static int valid_compat_regs(struct user_pt_regs *regs) {