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 01DAEC7618A for ; Mon, 20 Mar 2023 01:01:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231174AbjCTBBO (ORCPT ); Sun, 19 Mar 2023 21:01:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231139AbjCTA7z (ORCPT ); Sun, 19 Mar 2023 20:59:55 -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 751FD21A3B; Sun, 19 Mar 2023 17:56:14 -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 15478B80D4C; Mon, 20 Mar 2023 00:56:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E8CBC433EF; Mon, 20 Mar 2023 00:55:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1679273758; bh=P6vD6BAEdEhDdhlgw4psgjaRokQKZmpTxdO+jiaYJFY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X+qsEmSQs7xTzOEufqE/XUqx35jdnfGPnbIvL4PnZz/osR6neBbkpp0VmKrcAKmwT 1UDiflb9yYiJ76CtLd81o1ZwbyYvWz16ibFLvwGhyhLLHx2B7KZpE6iSzB2TwK24I5 KWMzv8hXJVf+kcOztHz+bghWrmm27//eG7jYKd8LldvI52g9aGYMbpHVCTxKS2UAj2 L4+xMxz3csiQZwY/9F9wvnrWSV3bcWmBkJrWJvBNSMmKKNQBzmwP6yapBZjKFapaAF YJby3At/bnL8ibHmiueaK9V3rBarYsQdLZ1S32oUQGQZlLG6TyAE0CwyUvRcH6k/xz 4Zykyj1jB5AIg== 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, wangkefeng.wang@huawei.com, chenhuacai@kernel.org, catalin.marinas@arm.com, akpm@linux-foundation.org, mpe@ellerman.id.au, linux-sh@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 17/17] sh: sanitize the flags on sigreturn Date: Sun, 19 Mar 2023 20:55:19 -0400 Message-Id: <20230320005521.1428820-17-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230320005521.1428820-1-sashal@kernel.org> References: <20230320005521.1428820-1-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 aa92cc933889d..6c7966e627758 100644 --- a/arch/sh/include/asm/processor_32.h +++ b/arch/sh/include/asm/processor_32.h @@ -50,6 +50,7 @@ #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 dd3092911efad..dc13702003f0f 100644 --- a/arch/sh/kernel/signal_32.c +++ b/arch/sh/kernel/signal_32.c @@ -115,6 +115,7 @@ 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]); @@ -130,6 +131,8 @@ 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