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 E7E44C7618A for ; Mon, 20 Mar 2023 01:31:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230007AbjCTBbq (ORCPT ); Sun, 19 Mar 2023 21:31:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230229AbjCTBbX (ORCPT ); Sun, 19 Mar 2023 21:31:23 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3801A241F3; Sun, 19 Mar 2023 18:24:13 -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 ams.source.kernel.org (Postfix) with ESMTPS id E0490B80B48; Mon, 20 Mar 2023 00:57:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4BF7AC433EF; Mon, 20 Mar 2023 00:57:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1679273851; bh=Q24NRcEzhgVm8UiR9gH3LzWlYm2ehh+5ZgK6JcpA32o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HxEFBklEL+JMTutn9jFkySG4ZU4nwwMAkF5f6o1ZMWRZgiG0rcOIGahSp5sBlhE6S rZYUmGTbLPN5RbKhcrYb0kBynCFMztZSr8DmxjDRf/PsGY1wdQIv+6QxUmyy/Ews4R Rn5Zc6PyW+VooCRsnxwVC3INeF6wOhoCLBM0ajYTNInrmcxp7pEEnUHxFUWjRJcpqV GPmZHMQnNp9MneV8ArDzbqJqPk0XlngxKlfqqDfiRwIEqjYgSJyiEdQuRTXuOC/sZ/ xV2uQOwPrcjNKJhL1/Ya+fmNt5m12UcuRqdC3QgJ9SSNyibQfNCXm1RZX8taWzhfxP OwwVzTftDsYng== 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, shorne@gmail.com, catalin.marinas@arm.com, chenhuacai@kernel.org, akpm@linux-foundation.org, wangkefeng.wang@huawei.com, linux-sh@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 9/9] sh: sanitize the flags on sigreturn Date: Sun, 19 Mar 2023 20:57:07 -0400 Message-Id: <20230320005707.1429405-9-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230320005707.1429405-1-sashal@kernel.org> References: <20230320005707.1429405-1-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 95100d8a0b7b4..fc94603724b86 100644 --- a/arch/sh/include/asm/processor_32.h +++ b/arch/sh/include/asm/processor_32.h @@ -57,6 +57,7 @@ #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 c46c0020ff55e..ce93ae78c3002 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