From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id C56546B046C for ; Fri, 18 Nov 2016 13:58:57 -0500 (EST) Received: by mail-pf0-f200.google.com with SMTP id i88so147763567pfk.3 for ; Fri, 18 Nov 2016 10:58:57 -0800 (PST) Received: from out01.mta.xmission.com (out01.mta.xmission.com. [166.70.13.231]) by mx.google.com with ESMTPS id f17si9378284pgi.11.2016.11.18.10.58.56 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 18 Nov 2016 10:58:56 -0800 (PST) From: ebiederm@xmission.com (Eric W. Biederman) References: <87twcbq696.fsf@x220.int.ebiederm.org> <20161018135031.GB13117@dhcp22.suse.cz> <8737jt903u.fsf@xmission.com> <20161018150507.GP14666@pc.thejh.net> <87twc9656s.fsf@xmission.com> <20161018191206.GA1210@laptop.thejh.net> <87r37dnz74.fsf@xmission.com> <87k2d5nytz.fsf_-_@xmission.com> <87y41kjn6l.fsf@xmission.com> <20161019172917.GE1210@laptop.thejh.net> <87pomwi5p2.fsf@xmission.com> <87pomwghda.fsf@xmission.com> <87twb6avk8.fsf_-_@xmission.com> <87oa1eavfx.fsf_-_@xmission.com> Date: Fri, 18 Nov 2016 12:56:15 -0600 In-Reply-To: (Kees Cook's message of "Thu, 17 Nov 2016 15:14:22 -0800") Message-ID: <87y40gpqgg.fsf@xmission.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [REVIEW][PATCH 1/3] ptrace: Capture the ptracer's creds not PT_PTRACE_CAP Sender: owner-linux-mm@kvack.org List-ID: To: Kees Cook Cc: Linux Containers , Oleg Nesterov , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Linux FS Devel , Michal Hocko , Jann Horn , Willy Tarreau , Andy Lutomirski Kees Cook writes: > On Thu, Nov 17, 2016 at 9:05 AM, Eric W. Biederman > wrote: >> >> When the flag PT_PTRACE_CAP was added the PTRACE_TRACEME path was >> overlooked. This can result in incorrect behavior when an application >> like strace traces an exec of a setuid executable. >> >> Further PT_PTRACE_CAP does not have enough information for making good >> security decisions as it does not report which user namespace the >> capability is in. This has already allowed one mistake through >> insufficient granulariy. >> >> I found this issue when I was testing another corner case of exec and >> discovered that I could not get strace to set PT_PTRACE_CAP even when >> running strace as root with a full set of caps. >> >> This change fixes the above issue with strace allowing stracing as >> root a setuid executable without disabling setuid. More fundamentaly >> this change allows what is allowable at all times, by using the correct >> information in it's decision. >> >> Cc: stable@vger.kernel.org >> Fixes: 4214e42f96d4 ("v2.4.9.11 -> v2.4.9.12") >> Signed-off-by: "Eric W. Biederman" >> --- >> [...] >> diff --git a/include/linux/sched.h b/include/linux/sched.h >> index 348f51b0ec92..8fe58255d219 100644 >> --- a/include/linux/sched.h >> +++ b/include/linux/sched.h >> @@ -1656,6 +1656,7 @@ struct task_struct { >> struct list_head cpu_timers[3]; >> >> /* process credentials */ >> + const struct cred __rcu *ptracer_cred; /* Tracer's dredentials at attach */ > > Typo: credentials. Thank you, fixed. Eric -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org