From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f197.google.com (mail-qk0-f197.google.com [209.85.220.197]) by kanga.kvack.org (Postfix) with ESMTP id F362B6B0495 for ; Sat, 19 Nov 2016 04:28:16 -0500 (EST) Received: by mail-qk0-f197.google.com with SMTP id x190so21817909qkb.5 for ; Sat, 19 Nov 2016 01:28:16 -0800 (PST) Received: from 1wt.eu (wtarreau.pck.nerim.net. [62.212.114.60]) by mx.google.com with ESMTP id e8si11168631wjh.217.2016.11.19.01.28.15 for ; Sat, 19 Nov 2016 01:28:15 -0800 (PST) Date: Sat, 19 Nov 2016 10:28:04 +0100 From: Willy Tarreau Subject: Re: [REVIEW][PATCH 0/3] Fixing ptrace vs exec vs userns interactions Message-ID: <20161119092804.GA13553@1wt.eu> References: <87y41kjn6l.fsf@xmission.com> <20161019172917.GE1210@laptop.thejh.net> <87pomwi5p2.fsf@xmission.com> <87pomwghda.fsf@xmission.com> <87twb6avk8.fsf_-_@xmission.com> <20161119071700.GA13347@1wt.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161119071700.GA13347@1wt.eu> Sender: owner-linux-mm@kvack.org List-ID: To: "Eric W. Biederman" Cc: Linux Containers , Oleg Nesterov , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Linux FS Devel , Michal Hocko , Jann Horn , Kees Cook , Andy Lutomirski On Sat, Nov 19, 2016 at 08:17:00AM +0100, Willy Tarreau wrote: > Hi Eric, > > On Thu, Nov 17, 2016 at 11:02:47AM -0600, Eric W. Biederman wrote: > > > > With everyone heading to Kernel Summit and Plumbers I put this set of > > patches down temporarily. Now is the time to take it back up and to > > make certain I am not missing something stupid in this set of patches. > > I couldn't get your patch set to apply to any of the kernels I tried, > I manually adjusted some parts but the second one has too many rejects. > What kernel should I apply this to ? Or maybe some preliminary patches > are needed ? OK I finally managed to get it to work on top of 4.8.9 (required less changes than master). I also had to drop the user_ns changes since there's no such user_ns in mm_struct there. I could run a test on it, that looks reasonable : FS: admin@vm:~$ strace -e trace=fstat,uname,ioctl,open uname open(0x7ffd01bbeeb0, O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open(0x7ffd01bbeeb0, O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open(0x7ffd01bbeeb0, O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open(0x7ffd01bbeeb0, O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open(0x7f3f9a1663e3, O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open(0x7ffd01bbeeb0, O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open(0x7ffd01bbeeb0, O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open(0x7ffd01bbeeb0, O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open(0x7ffd01bbeeb0, O_RDONLY|O_CLOEXEC) = 3 fstat(3, {...}) = 0 open(0x7ffd01bbee80, O_RDONLY|O_CLOEXEC) = 3 fstat(3, {...}) = 0 uname({...}) = 0 fstat(1, {...}) = 0 ioctl(1, SNDCTL_TMR_TIMEBASE or TCGETS, 0x7ffd01bbf400) = 0 admin@vm:~$ sudo strace -e trace=fstat,uname,ioctl,open uname open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/lib64/tls/x86_64/libpthread.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/lib64/tls/libpthread.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/lib64/x86_64/libpthread.so.0", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/lib64/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3 fstat(3, {st_mode=S_IFREG|0555, st_size=101312, ...}) = 0 open("/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3 fstat(3, {st_mode=S_IFREG|0555, st_size=1479016, ...}) = 0 uname({sys="Linux", node="vm", ...}) = 0 fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(4, 64), ...}) = 0 ioctl(1, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 opost isig icanon echo ...}) = 0 Network: admin@vm:~$ strace -e trace=socket,setsockopt,connect /tmp/nc 198.18.3 22 socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3 connect(3, {...}, 110) = -1 ENOENT (No such file or directory) socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3 connect(3, {...}, 110) = -1 ENOENT (No such file or directory) socket(PF_INET, SOCK_STREAM, IPPROTO_TCP) = 3 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, 0x7ffd2c26bdbc, 4) = 0 connect(3, {...}, 16) = 0 admin@vm:~$ sudo strace -e trace=socket,setsockopt,connect /tmp/nc 198.18.3 22 socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3 connect(3, {sa_family=AF_FILE, path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory) socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3 connect(3, {sa_family=AF_FILE, path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory) socket(PF_INET, SOCK_STREAM, IPPROTO_TCP) = 3 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 connect(3, {sa_family=AF_INET, sin_port=htons(22), sin_addr=inet_addr("198.18.0.3")}, 16) = 0 So in short now we can at least see what syscall fails eventhough we can't know why. I think it can be an acceptable trade-off. Thanks, Willy -- 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