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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, 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 E0222ECE561 for ; Tue, 25 Sep 2018 17:20:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9640820880 for ; Tue, 25 Sep 2018 17:20:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9640820880 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728147AbeIYX2t (ORCPT ); Tue, 25 Sep 2018 19:28:49 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:60823 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726400AbeIYX2s (ORCPT ); Tue, 25 Sep 2018 19:28:48 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out02.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1g4r0V-0000Zr-Jn; Tue, 25 Sep 2018 11:20:19 -0600 Received: from [105.184.227.67] (helo=x220.Home) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_CBC_SHA256:128) (Exim 4.87) (envelope-from ) id 1g4r0U-0001uD-C1; Tue, 25 Sep 2018 11:20:19 -0600 From: "Eric W. Biederman" To: linux-kernel@vger.kernel.org Cc: linux-api@vger.kernel.org, linux-arch@vger.kernel.org, Oleg Nesterov , Linus Torvalds , "Eric W. Biederman" Date: Tue, 25 Sep 2018 19:19:04 +0200 Message-Id: <20180925171906.19683-4-ebiederm@xmission.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <87h8idv6nw.fsf@xmission.com> References: <87h8idv6nw.fsf@xmission.com> X-XM-SPF: eid=1g4r0U-0001uD-C1;;;mid=<20180925171906.19683-4-ebiederm@xmission.com>;;;hst=in01.mta.xmission.com;;;ip=105.184.227.67;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19ERpqjCZhmsFTJC92C1QflMzMLeh7SunY= X-SA-Exim-Connect-IP: 105.184.227.67 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [REVIEW][PATCH 4/6] signal: Introduce copy_siginfo_from_user and use it's return value X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In preparation for using a smaller version of siginfo in the kernel introduce copy_siginfo_from_user and use it when siginfo is copied from userspace. Make the pattern for using copy_siginfo_from_user and copy_siginfo_from_user32 to capture the return value and return that value on error. This is a necessary prerequisite for using a smaller siginfo in the kernel than the kernel exports to userspace. Signed-off-by: "Eric W. Biederman" --- include/linux/signal.h | 1 + kernel/ptrace.c | 12 +++++------- kernel/signal.c | 25 ++++++++++++++++--------- 3 files changed, 22 insertions(+), 16 deletions(-) diff --git a/include/linux/signal.h b/include/linux/signal.h index 3d4cd5db30a9..de94c159bfb0 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -22,6 +22,7 @@ static inline void clear_siginfo(struct siginfo *info) } int copy_siginfo_to_user(struct siginfo __user *to, const struct siginfo *from); +int copy_siginfo_from_user(struct siginfo *to, const struct siginfo __user *from); enum siginfo_layout { SIL_KILL, diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 45f77a1b9c97..a807ff5cc1a9 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -919,9 +919,8 @@ int ptrace_request(struct task_struct *child, long request, break; case PTRACE_SETSIGINFO: - if (copy_from_user(&siginfo, datavp, sizeof siginfo)) - ret = -EFAULT; - else + ret = copy_siginfo_from_user(&siginfo, datavp); + if (!ret) ret = ptrace_setsiginfo(child, &siginfo); break; @@ -1215,10 +1214,9 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, break; case PTRACE_SETSIGINFO: - if (copy_siginfo_from_user32( - &siginfo, (struct compat_siginfo __user *) datap)) - ret = -EFAULT; - else + ret = copy_siginfo_from_user32( + &siginfo, (struct compat_siginfo __user *) datap); + if (!ret) ret = ptrace_setsiginfo(child, &siginfo); break; #ifdef CONFIG_HAVE_ARCH_TRACEHOOK diff --git a/kernel/signal.c b/kernel/signal.c index debb485a76db..c0e289e62d77 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2896,6 +2896,13 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from) return 0; } +int copy_siginfo_from_user(siginfo_t *to, const siginfo_t __user *from) +{ + if (copy_from_user(to, from, sizeof(struct siginfo))) + return -EFAULT; + return 0; +} + #ifdef CONFIG_COMPAT int copy_siginfo_to_user32(struct compat_siginfo __user *to, const struct siginfo *from) @@ -3323,8 +3330,9 @@ SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, siginfo_t __user *, uinfo) { siginfo_t info; - if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) - return -EFAULT; + int ret = copy_siginfo_from_user(&info, uinfo); + if (unlikely(ret)) + return ret; return do_rt_sigqueueinfo(pid, sig, &info); } @@ -3365,10 +3373,9 @@ SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, siginfo_t __user *, uinfo) { siginfo_t info; - - if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) - return -EFAULT; - + int ret = copy_siginfo_from_user(&info, uinfo); + if (unlikely(ret)) + return ret; return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); } @@ -3380,9 +3387,9 @@ COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo, struct compat_siginfo __user *, uinfo) { siginfo_t info; - - if (copy_siginfo_from_user32(&info, uinfo)) - return -EFAULT; + int ret = copy_siginfo_from_user32(&info, uinfo); + if (unlikely(ret)) + return ret; return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); } #endif -- 2.17.1