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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 215DAC7618A for ; Mon, 20 Mar 2023 01:06:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231599AbjCTBGy (ORCPT ); Sun, 19 Mar 2023 21:06:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231652AbjCTBFR (ORCPT ); Sun, 19 Mar 2023 21:05:17 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94E11206A3; Sun, 19 Mar 2023 17:58:26 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 21E1A611FA; Mon, 20 Mar 2023 00:57:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3A8C9C433EF; Mon, 20 Mar 2023 00:57:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1679273826; bh=6p5ARjw7NtCvfwJniRKWDiBaO/KRjZ5Zm2VYjEBLCuY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j6SmpHPzQNuE9H5L/cYAfz0l2rBXhm81xgAPTeB3Sc9TXmPjJBM2k/2RyGV4dvQSm j1cxgbFGX3rg6ulVmhZcpCUmRRmHzH5h8mhpvWKQIRsDDexJG03zqmDo2OFlt/GLXb r4/kaV4lHUEhN9wDE9RRIJN29CFNvk6epw+a9Vji6bca+RXle6MrcVE5FroLZ/GUrU 6oHYZMwHeZnGlmBmTBdnKBRzcxBAL6bbIbh3nMYCm49q48RB1jWO0L2WEvJpg2rlvL /vh9LKpjUyJ6pdeFrioJoresVcNYHrWEvkHw+qd8tQ6K2M79IoHXrg2Nr54jizXBBn h1SEJkF4HDeJQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Al Viro , Rich Felker , Linus Torvalds , Sasha Levin , ysato@users.sourceforge.jp, rmk+kernel@armlinux.org.uk, shorne@gmail.com, bcain@quicinc.com, mpe@ellerman.id.au, wangkefeng.wang@huawei.com, linux-sh@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 12/12] sh: sanitize the flags on sigreturn Date: Sun, 19 Mar 2023 20:56:35 -0400 Message-Id: <20230320005636.1429242-12-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230320005636.1429242-1-sashal@kernel.org> References: <20230320005636.1429242-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro [ Upstream commit 573b22ccb7ce9ab7f0539a2e11a9d3609a8783f5 ] We fetch %SR value from sigframe; it might have been modified by signal handler, so we can't trust it with any bits that are not modifiable in user mode. Signed-off-by: Al Viro Cc: Rich Felker Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- arch/sh/include/asm/processor_32.h | 1 + arch/sh/kernel/signal_32.c | 3 +++ 2 files changed, 4 insertions(+) diff --git a/arch/sh/include/asm/processor_32.h b/arch/sh/include/asm/processor_32.h index 0e0ecc0132e3b..58ae979798fa8 100644 --- a/arch/sh/include/asm/processor_32.h +++ b/arch/sh/include/asm/processor_32.h @@ -51,6 +51,7 @@ #define SR_FD 0x00008000 #define SR_MD 0x40000000 +#define SR_USER_MASK 0x00000303 // M, Q, S, T bits /* * DSP structure and data */ diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c index 24473fa6c3b63..f6e1a47ad7ca0 100644 --- a/arch/sh/kernel/signal_32.c +++ b/arch/sh/kernel/signal_32.c @@ -116,6 +116,7 @@ static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p) { unsigned int err = 0; + unsigned int sr = regs->sr & ~SR_USER_MASK; #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x) COPY(regs[1]); @@ -131,6 +132,8 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p COPY(sr); COPY(pc); #undef COPY + regs->sr = (regs->sr & SR_USER_MASK) | sr; + #ifdef CONFIG_SH_FPU if (boot_cpu_data.flags & CPU_HAS_FPU) { int owned_fp; -- 2.39.2