From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751718AbdDBW6V (ORCPT ); Sun, 2 Apr 2017 18:58:21 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:37295 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751245AbdDBW6S (ORCPT ); Sun, 2 Apr 2017 18:58:18 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Oleg Nesterov Cc: Andrew Morton , Aleksa Sarai , Andy Lutomirski , Attila Fazekas , Jann Horn , Kees Cook , Michal Hocko , Ulrich Obergfell , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org References: <20170213141452.GA30203@redhat.com> <20170224160354.GA845@redhat.com> <87shmv6ufl.fsf@xmission.com> <20170303173326.GA17899@redhat.com> <87tw7axlr0.fsf@xmission.com> <87d1dyw5iw.fsf@xmission.com> <87tw7aunuh.fsf@xmission.com> <87lgsmunmj.fsf_-_@xmission.com> <20170304170312.GB13131@redhat.com> <8760ir192p.fsf@xmission.com> <878tnkpv8h.fsf_-_@xmission.com> <874ly6a0h1.fsf_-_@xmission.com> Date: Sun, 02 Apr 2017 17:52:58 -0500 In-Reply-To: <874ly6a0h1.fsf_-_@xmission.com> (Eric W. Biederman's message of "Sun, 02 Apr 2017 17:50:02 -0500") Message-ID: <87k2728lrp.fsf_-_@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1cuoRo-0001FJ-9W;;;mid=<87k2728lrp.fsf_-_@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=67.3.234.240;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19e/izKFp7fk3vRSdfW+EZUnYws7LXfwL8= X-SA-Exim-Connect-IP: 67.3.234.240 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 TVD_RCVD_IP Message was received from an IP address * 0.7 XMSubLong Long Subject * 1.5 TR_Symld_Words too many words that have symbols inside * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa05 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa05 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **;Oleg Nesterov X-Spam-Relay-Country: X-Spam-Timing: total 5550 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 3.8 (0.1%), b_tie_ro: 2.6 (0.0%), parse: 1.42 (0.0%), extract_message_metadata: 17 (0.3%), get_uri_detail_list: 1.51 (0.0%), tests_pri_-1000: 9 (0.2%), tests_pri_-950: 1.76 (0.0%), tests_pri_-900: 1.34 (0.0%), tests_pri_-400: 22 (0.4%), check_bayes: 21 (0.4%), b_tokenize: 8 (0.1%), b_tok_get_all: 6 (0.1%), b_comp_prob: 2.2 (0.0%), b_tok_touch_all: 2.7 (0.0%), b_finish: 0.72 (0.0%), tests_pri_0: 143 (2.6%), check_dkim_signature: 0.62 (0.0%), check_dkim_adsp: 3.1 (0.1%), tests_pri_500: 5346 (96.3%), poll_dns_idle: 5337 (96.2%), rewrite_mail: 0.00 (0.0%) Subject: [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Old threading libraries used CLONE_SIGHAND without clone thread. Modern threadding libraries always use CLONE_SIGHAND | CLONE_THREAD. Therefore let's simplify our lives and stop supporting a case no one cares about. Signed-off-by: "Eric W. Biederman" --- kernel/fork.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/fork.c b/kernel/fork.c index fe6f1bf32bb9..0632ac1180be 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1515,6 +1515,13 @@ static __latent_entropy struct task_struct *copy_process( if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND)) return ERR_PTR(-EINVAL); + /* Disallow CLONE_THREAD with a shared SIGHAND structure. No + * one cares and supporting it leads to unnecessarily complex + * code. + */ + if ((clone_flags & CLONE_THREAD) && (atomic_read(¤t->sighand->count) > 1)) + return ERR_PTR(-EINVAL); + /* * Shared signal handlers imply shared VM. By way of the above, * thread groups also imply shared VM. Blocking this case allows -- 2.10.1 From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman) Subject: [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct Date: Sun, 02 Apr 2017 17:52:58 -0500 Message-ID: <87k2728lrp.fsf_-_@xmission.com> References: <20170213141452.GA30203@redhat.com> <20170224160354.GA845@redhat.com> <87shmv6ufl.fsf@xmission.com> <20170303173326.GA17899@redhat.com> <87tw7axlr0.fsf@xmission.com> <87d1dyw5iw.fsf@xmission.com> <87tw7aunuh.fsf@xmission.com> <87lgsmunmj.fsf_-_@xmission.com> <20170304170312.GB13131@redhat.com> <8760ir192p.fsf@xmission.com> <878tnkpv8h.fsf_-_@xmission.com> <874ly6a0h1.fsf_-_@xmission.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <874ly6a0h1.fsf_-_-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> (Eric W. Biederman's message of "Sun, 02 Apr 2017 17:50:02 -0500") Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Oleg Nesterov Cc: Andrew Morton , Aleksa Sarai , Andy Lutomirski , Attila Fazekas , Jann Horn , Kees Cook , Michal Hocko , Ulrich Obergfell , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@vger.kernel.org Old threading libraries used CLONE_SIGHAND without clone thread. Modern threadding libraries always use CLONE_SIGHAND | CLONE_THREAD. Therefore let's simplify our lives and stop supporting a case no one cares about. Signed-off-by: "Eric W. Biederman" --- kernel/fork.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/fork.c b/kernel/fork.c index fe6f1bf32bb9..0632ac1180be 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1515,6 +1515,13 @@ static __latent_entropy struct task_struct *copy_process( if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND)) return ERR_PTR(-EINVAL); + /* Disallow CLONE_THREAD with a shared SIGHAND structure. No + * one cares and supporting it leads to unnecessarily complex + * code. + */ + if ((clone_flags & CLONE_THREAD) && (atomic_read(¤t->sighand->count) > 1)) + return ERR_PTR(-EINVAL); + /* * Shared signal handlers imply shared VM. By way of the above, * thread groups also imply shared VM. Blocking this case allows -- 2.10.1