From patchwork Wed May 18 22:53:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 574462 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 B1308C433F5 for ; Wed, 18 May 2022 22:55:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231129AbiERWzf (ORCPT ); Wed, 18 May 2022 18:55:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230466AbiERWzA (ORCPT ); Wed, 18 May 2022 18:55:00 -0400 Received: from out03.mta.xmission.com (out03.mta.xmission.com [166.70.13.233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F68B2265DF; Wed, 18 May 2022 15:54:59 -0700 (PDT) Received: from in01.mta.xmission.com ([166.70.13.51]:33018) by out03.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nrSZG-00CkZV-Mj; Wed, 18 May 2022 16:54:58 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:38724 helo=localhost.localdomain) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nrSZF-002Z0O-HE; Wed, 18 May 2022 16:54:58 -0600 From: "Eric W. Biederman" To: linux-kernel@vger.kernel.org Cc: rjw@rjwysocki.net, Oleg Nesterov , mingo@kernel.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, mgorman@suse.de, bigeasy@linutronix.de, Will Deacon , tj@kernel.org, linux-pm@vger.kernel.org, Peter Zijlstra , Richard Weinberger , Anton Ivanov , Johannes Berg , linux-um@lists.infradead.org, Chris Zankel , Max Filippov , linux-xtensa@linux-xtensa.org, Kees Cook , Jann Horn , linux-ia64@vger.kernel.org, Robert OCallahan , Kyle Huey , Richard Henderson , Ivan Kokshaysky , Matt Turner , Jason Wessel , Daniel Thompson , Douglas Anderson , Douglas Miller , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , "Eric W. Biederman" Date: Wed, 18 May 2022 17:53:48 -0500 Message-Id: <20220518225355.784371-9-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <871qwq5ucx.fsf_-_@email.froward.int.ebiederm.org> References: <871qwq5ucx.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nrSZF-002Z0O-HE; ; ; mid=<20220518225355.784371-9-ebiederm@xmission.com>; ; ; hst=in01.mta.xmission.com; ; ; ip=68.227.174.4; ; ; frm=ebiederm@xmission.com; ; ; spf=softfail X-XM-AID: U2FsdGVkX19tbqiOJHWnZVuKgNQ7Jp3oXCI1nNuPXUo= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH 09/16] ptrace: In ptrace_setsiginfo deal with invalid si_signo X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org If the tracer calls PTRACE_SETSIGINFO it only has an effect if the tracee is stopped in ptrace_signal. When one of PTRACE_DETACH, PTRACE_SINGLESTEP, PTRACE_SINGLEBLOCK, PTRACE_SYSEMU, PTRACE_SYSEMU_SINGLESTEP, PTRACE_SYSCALL, or PTRACE_CONT pass in a signel number to continue with the kernel validates that signal number and the ptrace_signal verifies the signal number matches the si_signo, before the siginfo is used. As the signal number to continue with is verified to be a valid signal number the signal number in si_signo must be a valid signal number. Make this obvious and avoid needing checks later by immediately clearing siginfo if si_signo is not valid. Signed-off-by: "Eric W. Biederman" --- kernel/ptrace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index a24eed725cec..a0a07d140751 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -716,7 +716,9 @@ static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t * if (unlikely(!child->last_siginfo)) return -EINVAL; - copy_siginfo(child->last_siginfo, info); + clear_siginfo(child->last_siginfo); + if (valid_signal(info->si_signo)) + copy_siginfo(child->last_siginfo, info); return 0; }