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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 CAD4BC388F9 for ; Thu, 19 Nov 2020 22:20:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DB2B2224A for ; Thu, 19 Nov 2020 22:20:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=home.drummond.us header.i=@home.drummond.us header.b="E1o03DRp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726851AbgKSWUN (ORCPT ); Thu, 19 Nov 2020 17:20:13 -0500 Received: from drummond.us ([74.95.14.229]:4564 "EHLO talisker.home.drummond.us" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726464AbgKSWUN (ORCPT ); Thu, 19 Nov 2020 17:20:13 -0500 X-Greylist: delayed 469 seconds by postgrey-1.27 at vger.kernel.org; Thu, 19 Nov 2020 17:20:12 EST Received: from talisker.home.drummond.us (localhost [127.0.0.1]) by talisker.home.drummond.us (8.15.2/8.15.2/Debian-20) with ESMTP id 0AJMBolN1515759; Thu, 19 Nov 2020 14:11:50 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=home.drummond.us; s=default; t=1605823911; bh=Ayx7/03KKR9LNFXEVXiNjLwjKsBf8QCVWMy0RTPXC3A=; h=From:To:Subject:Date:From; b=E1o03DRpQSuWoGSlGl/mfkHO4gTUiBjNeD5f6fi2f+8uQRlkMJsIGjBsUAD1WUIor wY6ioximfxcU0h2Rc6mBdt//7Wiu/bD0YXlVqj4l8li7SJ7USPbnSoxqwdILOonX1d viNn1+6TPmngWXWSLPu9InO/rPuI3g8JEi4Epcmvw9dHb10Z4OnoRlNRJCWBLIUW3T C6Om90k6BrPMBWx80OFdw+0vd2gKGIy+dXP7UzxWF4cWdf7qQ3kgVOa8jjrqQlWjkG uSRaCWlrXIiWxWeTE/ljDWJIe41gKCDkp8Eo7fE2WAacJ7rKxwoXRleiMph+lc6X0i rZU9CjFTW4KxA== Received: (from walt@localhost) by talisker.home.drummond.us (8.15.2/8.15.2/Submit) id 0AJMBlFG1515758; Thu, 19 Nov 2020 14:11:47 -0800 From: Walt Drummond To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, viro@zeniv.linux.org.uk, brgerst@gmail.com, linux@dominikbrodowski.net, walt@drummond.us, gustavoars@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] x86/signals: Fix save/restore signal stack to correctly support sigset_t Date: Thu, 19 Nov 2020 14:11:33 -0800 Message-Id: <20201119221132.1515696-1-walt@drummond.us> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The macro unsafe_put_sigmask() only handles the first 64 bits of the sigmask_t, which works today. However, if the definition of the sigset_t structure ever changed, this would fail to setup/restore the signal stack properly and likely corrupt the sigset. This patch updates unsafe_put_sigmask() to correctly save all the fields in the sigmask_t struct, and adds unsafe_put_compat_sigmask() to handle the compat_sigset_t cases. Signed-off-by: Walt Drummond --- arch/x86/kernel/signal.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index be0d7d4152ec..4d5134b4bb5f 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -203,11 +203,18 @@ do { \ goto label; \ } while(0); -#define unsafe_put_sigmask(set, frame, label) \ +#define unsafe_put_compat_sigmask(set, frame, label) \ unsafe_put_user(*(__u64 *)(set), \ (__u64 __user *)&(frame)->uc.uc_sigmask, \ label) +#define unsafe_put_sigmask(set, frame, label) \ +do { \ + int i; \ + for (i = 0; i < _NSIG_WORDS; i++) \ + unsafe_put_user((set)->sig[i], &(frame)->uc.uc_sigmask.sig[i], label); \ +} while(0); + /* * Set up a signal frame. */ @@ -566,7 +573,7 @@ static int x32_setup_rt_frame(struct ksignal *ksig, restorer = ksig->ka.sa.sa_restorer; unsafe_put_user(restorer, (unsigned long __user *)&frame->pretcode, Efault); unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault); - unsafe_put_sigmask(set, frame, Efault); + unsafe_put_compat_sigmask(set, frame, Efault); user_access_end(); if (ksig->ka.sa.sa_flags & SA_SIGINFO) { @@ -643,7 +650,7 @@ SYSCALL_DEFINE0(rt_sigreturn) frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); if (!access_ok(frame, sizeof(*frame))) goto badframe; - if (__get_user(*(__u64 *)&set, (__u64 __user *)&frame->uc.uc_sigmask)) + if (copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(sigset_t))) goto badframe; if (__get_user(uc_flags, &frame->uc.uc_flags)) goto badframe; -- 2.27.0