From: Christian Brauner <christian.brauner@ubuntu.com>
To: Bernd Edlinger <bernd.edlinger@hotmail.de>
Cc: Kees Cook <keescook@chromium.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Jann Horn <jannh@google.com>, Jonathan Corbet <corbet@lwn.net>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Oleg Nesterov <oleg@redhat.com>,
Frederic Weisbecker <frederic@kernel.org>,
Andrei Vagin <avagin@gmail.com>, Ingo Molnar <mingo@kernel.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Yuyang Du <duyuyang@gmail.com>,
David Hildenbrand <david@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Anshuman Khandual <anshuman.khandual@arm.com>,
David Howells <dhowells@redhat.com>,
James Morris <jamorris@linux.microsoft.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Shakeel Butt <shakeelb@google.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
Christian Kellner <christian@kellner.me>,
Andrea Arcangeli <aarcange@redhat.com>,
Aleksa Sarai <cyphar@cyphar.com>,
"Dmitry V. Levin" <ldv@altlinux.org>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: [PATCHv4] exec: Fix a deadlock in ptrace
Date: Wed, 4 Mar 2020 16:30:02 +0100 [thread overview]
Message-ID: <20200304153002.ck77l6nifnvn647p@wittgenstein> (raw)
In-Reply-To: <AM6PR03MB5170A15099986CEC3189F251E4E40@AM6PR03MB5170.eurprd03.prod.outlook.com>
On Tue, Mar 03, 2020 at 08:08:26AM +0000, Bernd Edlinger wrote:
> On 3/3/20 6:29 AM, Kees Cook wrote:
> > On Tue, Mar 03, 2020 at 04:54:34AM +0000, Bernd Edlinger wrote:
> >> On 3/3/20 3:26 AM, Kees Cook wrote:
> >>> On Mon, Mar 02, 2020 at 10:18:07PM +0000, Bernd Edlinger wrote:
> >>>> [...]
> >>>
> >>> If I'm reading this patch correctly, this changes the lifetime of the
> >>> cred_guard_mutex lock to be:
> >>> - during prepare_bprm_creds()
> >>> - from flush_old_exec() through install_exec_creds()
> >>> Before, cred_guard_mutex was held from prepare_bprm_creds() through
> >>> install_exec_creds().
> >
> > BTW, I think the effect of this change (i.e. my paragraph above) should
> > be distinctly called out in the commit log if this solution moves
> > forward.
> >
>
> Okay, will do.
>
> >>> That means, for example, that check_unsafe_exec()'s documented invariant
> >>> is violated:
> >>> /*
> >>> * determine how safe it is to execute the proposed program
> >>> * - the caller must hold ->cred_guard_mutex to protect against
> >>> * PTRACE_ATTACH or seccomp thread-sync
> >>> */
> >>
> >> Oh, right, I haven't understood that hint...
> >
> > I know no_new_privs is checked there, but I haven't studied the
> > PTRACE_ATTACH part of that comment. If that is handled with the new
> > check, this comment should be updated.
> >
>
> Okay, I change that comment to:
>
> /*
> * determine how safe it is to execute the proposed program
> * - the caller must have set ->cred_locked_in_execve to protect against
> * PTRACE_ATTACH or seccomp thread-sync
> */
>
> >>> I think it also means that the potentially multiple invocations
> >>> of bprm_fill_uid() (via prepare_binprm() via binfmt_script.c and
> >>> binfmt_misc.c) would be changing bprm->cred details (uid, gid) without
> >>> a lock (another place where current's no_new_privs is evaluated).
> >>
> >> So no_new_privs can change from 0->1, but should not
> >> when execve is running.
> >>
> >> As long as the calling thread is in execve it won't do this,
> >> and the only other place, where it may set for other threads
> >> is in seccomp_sync_threads, but that can easily be avoided see below.
> >
> > Yeah, everything was fine until I had to go complicate things with
> > TSYNC. ;) The real goal is making sure an exec cannot gain privs while
> > later gaining a seccomp filter from an unpriv process. The no_new_privs
> > flag was used to control this, but it required that the filter not get
> > applied during exec.
> >
> >>> Related, it also means that cred_guard_mutex is unheld for every
> >>> invocation of search_binary_handler() (which can loop via the previously
> >>> mentioned binfmt_script.c and binfmt_misc.c), if any of them have hidden
> >>> dependencies on cred_guard_mutex. (Thought I only see bprm_fill_uid()
> >>> currently.)
> >>>
> >>> For seccomp, the expectations about existing thread states risks races
> >>> too. There are two locks held for TSYNC:
> >>> - current->sighand->siglock is held to keep new threads from
> >>> appearing/disappearing, which would destroy filter refcounting and
> >>> lead to memory corruption.
> >>
> >> I don't understand what you mean here.
> >> How can this lead to memory corruption?
> >
> > Mainly this is a matter of how seccomp manages its filter hierarchy
> > (since the filters are shared through process ancestry), so if a thread
> > appears in the middle of TSYNC it may be racing another TSYNC and break
> > ancestry, leading to bad reference counting on process death, etc.
> > (Though, yes, with refcount_t now, things should never corrupt, just
> > waste memory.)
> >
>
> I assume for now, that the current->sighand->siglock held while iterating all
> threads is sufficient here.
>
> >>> - cred_guard_mutex is held to keep no_new_privs in sync with filters to
> >>> avoid no_new_privs and filter confusion during exec, which could
> >>> lead to exploitable setuid conditions (see below).
> >>>
> >>> Just racing a malicious thread during TSYNC is not a very strong
> >>> example (a malicious thread could do lots of fun things to "current"
> >>> before it ever got near calling TSYNC), but I think there is the risk
> >>> of mismatched/confused states that we don't want to allow. One is a
> >>> particularly bad state that could lead to privilege escalations (in the
> >>> form of the old "sendmail doesn't check setuid" flaw; if a setuid process
> >>> has a filter attached that silently fails a priv-dropping setuid call
> >>> and continues execution with elevated privs, it can be tricked into
> >>> doing bad things on behalf of the unprivileged parent, which was the
> >>> primary goal of the original use of cred_guard_mutex with TSYNC[1]):
> >>>
> >>> thread A clones thread B
> >>> thread B starts setuid exec
> >>> thread A sets no_new_privs
> >>> thread A calls seccomp with TSYNC
> >>> thread A in seccomp_sync_threads() sets seccomp filter on self and thread B
> >>> thread B passes check_unsafe_exec() with no_new_privs unset
> >>> thread B reaches bprm_fill_uid() with no_new_privs unset and gains privs
> >>> thread A still in seccomp_sync_threads() sets no_new_privs on thread B
> >>> thread B finishes exec, now running with elevated privs, a filter chosen
> >>> by thread A, _and_ nnp set (which doesn't matter)
> >>>
> >>> With the original locking, thread B will fail check_unsafe_exec()
> >>> because filter and nnp state are changed together, with "atomicity"
> >>> protected by the cred_guard_mutex.
> >>>
> >>
> >> Ah, good point, thanks!
> >>
> >> This can be fixed by checking current->signal->cred_locked_for_ptrace
> >> while the cred_guard_mutex is locked, like this for instance:
> >>
> >> diff --git a/kernel/seccomp.c b/kernel/seccomp.c
> >> index b6ea3dc..377abf0 100644
> >> --- a/kernel/seccomp.c
> >> +++ b/kernel/seccomp.c
> >> @@ -342,6 +342,9 @@ static inline pid_t seccomp_can_sync_threads(void)
> >> BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex));
> >> assert_spin_locked(¤t->sighand->siglock);
> >>
> >> + if (current->signal->cred_locked_for_ptrace)
> >> + return -EAGAIN;
> >> +
> >
> > Hmm. I guess something like that could work. TSYNC expects to be able to
> > report _which_ thread wrecked the call, though... I wonder if in_execve
> > could be used to figure out the offending thread. Hm, nope, that would
> > be outside of lock too (and all users are "current" right now, so the
> > lock wasn't needed before).
> >
>
> I could move that in_execve = 1 to prepare_bprm_creds, if it really matters,
> but the caller will die quickly and cannot do anything with that information
> when another thread executes execve, right?
>
> >> /* Validate all threads being eligible for synchronization. */
> >> caller = current;
> >> for_each_thread(caller, thread) {
> >>
> >>
> >>> And this is just the bad state I _can_ see. I'm worried there are more...
> >>>
> >>> All this said, I do see a small similarity here to the work I did to
> >>> stabilize stack rlimits (there was an ongoing problem with making multiple
> >>> decisions for the bprm based on current's state -- but current's state
> >>> was mutable during exec). For this, I saved rlim_stack to bprm and ignored
> >>> current's copy until exec ended and then stored bprm's copy into current.
> >>> If the only problem anyone can see here is the handling of no_new_privs,
> >>> we might be able to solve that similarly, at least disentangling tsync/nnp
> >>> from cred_guard_mutex.
> >>>
> >>
> >> I still think that is solvable with using cred_locked_for_ptrace and
> >> simply make the tsync fail if it would otherwise be blocked.
> >
> > I wonder if we can find a better name than "cred_locked_for_ptrace"?
> > Maybe "cred_unfinished" or "cred_locked_in_exec" or something?
> >
>
> Yeah, I'd go with "cred_locked_in_execve".
>
> > And the comment on bool cred_locked_for_ptrace should mention that
> > access is only allowed under cred_guard_mutex lock.
> >
>
> okay.
>
> >>>> + sig->cred_locked_for_ptrace = false;
> >
> > This is redundant to the zalloc -- I think you can drop it (unless
> > someone wants to keep it for clarify?)
> >
>
> I'll remove that here and in init/init_task.c
>
> > Also, I think cred_locked_for_ptrace needs checking deeper, in
> > __ptrace_may_access(), not in ptrace_attach(), since LOTS of things make
> > calls to ptrace_may_access() holding cred_guard_mutex, expecting that to
> > be sufficient to see a stable version of the thread...
> >
>
> No, these need to be addressed individually, but most users just want
> to know if the current credentials are sufficient at this moment, but will
> not change the credentials, as ptrace and TSYNC do.
>
> BTW: Not all users have cred_guard_mutex, see mm/migrate.c,
> mm/mempolicy.c, kernel/futex.c, fs/proc/namespaces.c etc.
> So adding an access to cred_locked_for_execve in ptrace_may_access is
> probably not an option.
That could be solved by e.g. adding ptrace_may_access_{no}exec() taking
cred_guard_mutex.
next prev parent reply other threads:[~2020-03-04 15:30 UTC|newest]
Thread overview: 202+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-01 11:27 [PATCH] exec: Fix a deadlock in ptrace Bernd Edlinger
2020-03-01 15:13 ` Aleksa Sarai
2020-03-01 15:58 ` Christian Brauner
2020-03-01 17:46 ` Bernd Edlinger
2020-03-01 18:20 ` Christian Brauner
2020-03-01 17:24 ` Bernd Edlinger
2020-03-01 18:21 ` Jann Horn
2020-03-01 18:52 ` Christian Brauner
2020-03-01 19:00 ` Bernd Edlinger
2020-03-01 20:00 ` Jann Horn
2020-03-01 20:34 ` [PATCHv2] " Bernd Edlinger
2020-03-02 6:38 ` Eric W. Biederman
2020-03-02 15:43 ` Bernd Edlinger
2020-03-02 15:57 ` Eric W. Biederman
2020-03-02 16:02 ` Bernd Edlinger
2020-03-02 16:17 ` Eric W. Biederman
2020-03-02 16:43 ` Jann Horn
2020-03-02 17:01 ` Bernd Edlinger
2020-03-02 17:37 ` Jann Horn
2020-03-02 17:42 ` christian
2020-03-02 18:08 ` Jann Horn
2020-03-02 20:10 ` [PATCHv3] " Bernd Edlinger
2020-03-02 20:28 ` Bernd Edlinger
2020-03-03 20:13 ` [PATCHv2] " Eric W. Biederman
2020-03-02 17:13 ` Bernd Edlinger
2020-03-02 21:49 ` Eric W. Biederman
2020-03-02 22:00 ` Bernd Edlinger
2020-03-02 22:18 ` [PATCHv4] " Bernd Edlinger
2020-03-03 2:26 ` Kees Cook
2020-03-03 4:54 ` Bernd Edlinger
2020-03-03 5:29 ` Kees Cook
2020-03-03 8:08 ` Bernd Edlinger
2020-03-03 8:34 ` Christian Brauner
2020-03-03 8:43 ` Christian Brauner
2020-03-04 15:30 ` Christian Brauner [this message]
2020-03-03 8:58 ` Christian Brauner
2020-03-03 10:34 ` Bernd Edlinger
2020-03-03 11:23 ` Bernd Edlinger
2020-03-03 14:20 ` Christian Brauner
2020-03-03 13:02 ` [PATCHv5] " Bernd Edlinger
2020-03-03 15:18 ` Eric W. Biederman
2020-03-03 16:48 ` Bernd Edlinger
2020-03-03 17:01 ` Christian Brauner
2020-03-03 17:20 ` Christian Brauner
2020-03-03 20:08 ` Eric W. Biederman
2020-03-04 14:37 ` Bernd Edlinger
2020-03-04 16:33 ` Eric W. Biederman
2020-03-04 21:49 ` Bernd Edlinger
2020-03-04 21:56 ` [PATCHv6] " Bernd Edlinger
2020-03-05 18:36 ` Bernd Edlinger
2020-03-05 21:14 ` [PATCH 0/2] Infrastructure to allow fixing exec deadlocks Eric W. Biederman
2020-03-05 21:15 ` [PATCH 1/2] exec: Properly mark the point of no return Eric W. Biederman
2020-03-05 22:34 ` Bernd Edlinger
2020-03-06 5:19 ` Eric W. Biederman
2020-03-05 22:56 ` Bernd Edlinger
2020-03-06 5:09 ` Eric W. Biederman
2020-03-06 16:26 ` Bernd Edlinger
2020-03-06 17:16 ` Eric W. Biederman
2020-03-05 21:16 ` [PATCH 2/2] exec: Add a exec_update_mutex to replace cred_guard_mutex Eric W. Biederman
2020-03-05 21:51 ` Bernd Edlinger
2020-03-06 5:17 ` Eric W. Biederman
2020-03-06 11:46 ` Bernd Edlinger
2020-03-06 21:18 ` Eric W. Biederman
2020-03-06 19:16 ` Bernd Edlinger
2020-03-06 21:58 ` Eric W. Biederman
2020-03-06 22:29 ` Eric W. Biederman
2020-03-07 1:03 ` Eric W. Biederman
2020-03-08 12:58 ` [PATCH] exec: make de_thread alloc new signal struct earlier Bernd Edlinger
2020-03-08 18:12 ` Eric W. Biederman
2020-03-05 22:31 ` [PATCH 0/2] Infrastructure to allow fixing exec deadlocks Bernd Edlinger
2020-03-06 5:06 ` Eric W. Biederman
2020-03-08 21:34 ` [PATCH 0/5] " Eric W. Biederman
2020-03-08 21:35 ` [PATCH v2 1/5] exec: Only compute current once in flush_old_exec Eric W. Biederman
2020-03-09 13:56 ` Bernd Edlinger
2020-03-09 17:34 ` Eric W. Biederman
2020-03-09 17:56 ` Bernd Edlinger
2020-03-09 19:27 ` Bernd Edlinger
2020-03-10 20:17 ` Kees Cook
2020-03-10 21:12 ` Christian Brauner
2020-03-08 21:36 ` [PATCH v2 2/5] exec: Factor unshare_sighand out of de_thread and call it separately Eric W. Biederman
2020-03-09 19:28 ` Bernd Edlinger
2020-03-10 20:29 ` Kees Cook
2020-03-10 20:34 ` Bernd Edlinger
2020-03-10 20:57 ` Kees Cook
2020-03-10 21:21 ` Christian Brauner
2020-03-08 21:36 ` [PATCH v2 3/5] exec: Move cleanup of posix timers on exec out of de_thread Eric W. Biederman
2020-03-09 19:30 ` Bernd Edlinger
2020-03-09 19:59 ` Christian Brauner
2020-03-09 20:06 ` Eric W. Biederman
2020-03-09 20:17 ` Christian Brauner
2020-03-09 20:48 ` Eric W. Biederman
2020-03-10 8:55 ` Christian Brauner
2020-03-10 18:52 ` [PATCH] pidfd: Stop taking cred_guard_mutex Eric W. Biederman
2020-03-10 19:15 ` Christian Brauner
2020-03-10 19:16 ` Jann Horn
2020-03-10 19:27 ` Eric W. Biederman
2020-03-10 20:00 ` Jann Horn
2020-03-10 20:10 ` Jann Horn
2020-03-10 20:22 ` Bernd Edlinger
2020-03-11 6:11 ` Bernd Edlinger
2020-03-11 14:56 ` Jann Horn
2020-03-10 20:57 ` Eric W. Biederman
2020-03-10 21:29 ` Christian Brauner
2020-03-11 18:49 ` Kees Cook
2020-03-14 9:12 ` [PATCH] pidfd: Use new infrastructure to fix deadlocks in execve Bernd Edlinger
2020-03-10 20:16 ` [PATCH v2 3/5] exec: Move cleanup of posix timers on exec out of de_thread Kees Cook
2020-03-10 20:31 ` Kees Cook
2020-03-10 20:57 ` Jann Horn
2020-03-10 21:05 ` Eric W. Biederman
2020-03-10 21:22 ` Christian Brauner
2020-03-08 21:38 ` [PATCH v2 4/5] exec: Move exec_mmap right after de_thread in flush_old_exec Eric W. Biederman
2020-03-09 19:34 ` Bernd Edlinger
2020-03-09 19:45 ` Eric W. Biederman
2020-03-09 19:52 ` Bernd Edlinger
2020-03-09 19:58 ` Eric W. Biederman
2020-03-09 20:03 ` Bernd Edlinger
2020-03-09 20:35 ` Eric W. Biederman
2020-03-10 20:44 ` Kees Cook
2020-03-10 21:20 ` Eric W. Biederman
2020-03-10 20:47 ` Kees Cook
2020-03-10 21:09 ` Eric W. Biederman
2020-03-08 21:38 ` [PATCH v2 5/5] exec: Add a exec_update_mutex to replace cred_guard_mutex Eric W. Biederman
2020-03-09 13:45 ` Bernd Edlinger
2020-03-09 17:40 ` Eric W. Biederman
2020-03-09 18:01 ` Bernd Edlinger
2020-03-09 18:10 ` Eric W. Biederman
2020-03-09 18:24 ` Eric W. Biederman
2020-03-09 18:36 ` Eric W. Biederman
2020-03-09 18:47 ` Bernd Edlinger
2020-03-09 19:02 ` Eric W. Biederman
2020-03-09 19:24 ` Bernd Edlinger
2020-03-09 19:35 ` Eric W. Biederman
2020-03-09 19:39 ` Eric W. Biederman
2020-03-10 13:43 ` [PATCH 0/4] Use new infrastructure to fix deadlocks in execve Bernd Edlinger
2020-03-10 15:35 ` Eric W. Biederman
2020-03-10 17:44 ` [PATCH 0/4] Use new infrastructure in more simple cases Bernd Edlinger
2020-03-10 17:45 ` [PATCH 1/4] kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve Bernd Edlinger
2020-03-10 19:01 ` Eric W. Biederman
2020-03-10 19:42 ` Bernd Edlinger
2020-03-10 17:45 ` [PATCH 2/4] proc: " Bernd Edlinger
2020-03-11 18:59 ` Kees Cook
2020-03-11 19:10 ` Kees Cook
2020-03-11 19:38 ` Bernd Edlinger
2020-03-10 17:45 ` [PATCH 3/4] proc: io_accounting: " Bernd Edlinger
2020-03-10 19:06 ` Eric W. Biederman
[not found] ` <AM6PR03MB5170A29F8D885147F1A3981EE4FF0@AM6PR03MB5170.eurprd03.prod.outlook.com>
2020-03-10 21:25 ` Eric W. Biederman
2020-03-11 19:08 ` Kees Cook
2020-03-11 19:48 ` Bernd Edlinger
2020-03-11 19:48 ` Eric W. Biederman
2020-03-10 17:45 ` [PATCH 4/4] perf: " Bernd Edlinger
2020-03-10 13:43 ` [PATCH 1/4] exec: Fix a deadlock in ptrace Bernd Edlinger
2020-03-10 15:13 ` Eric W. Biederman
2020-03-10 15:17 ` Bernd Edlinger
2020-03-10 21:00 ` Kees Cook
2020-03-10 13:44 ` [PATCH 2/4] selftests/ptrace: add test cases for dead-locks Bernd Edlinger
2020-03-10 21:36 ` Kees Cook
2020-03-10 22:41 ` Dmitry V. Levin
2020-03-10 13:44 ` [PATCH 3/4] mm: docs: Fix a comment in process_vm_rw_core Bernd Edlinger
2020-03-11 18:53 ` Kees Cook
2020-03-10 13:44 ` [PATCH 4/4] kernel: doc: remove outdated comment cred.c Bernd Edlinger
2020-03-11 18:54 ` Kees Cook
2020-03-09 19:33 ` [PATCH v2 5/5] exec: Add a exec_update_mutex to replace cred_guard_mutex Dmitry V. Levin
2020-03-09 19:42 ` Eric W. Biederman
2020-03-10 20:55 ` Kees Cook
2020-03-10 21:02 ` Eric W. Biederman
2020-03-10 21:21 ` Jann Horn
2020-03-10 21:30 ` Eric W. Biederman
2020-03-10 23:21 ` Jann Horn
2020-03-11 0:15 ` Eric W. Biederman
2020-03-11 6:33 ` Bernd Edlinger
2020-03-11 13:18 ` Qian Cai
2020-03-12 10:27 ` Kirill Tkhai
2020-03-12 12:24 ` Eric W. Biederman
2020-03-12 13:45 ` Kirill Tkhai
2020-03-12 14:38 ` Eric W. Biederman
2020-03-12 15:23 ` Kirill Tkhai
2020-03-13 1:05 ` Bernd Edlinger
2020-03-13 9:13 ` Kirill Tkhai
2020-03-14 9:11 ` [PATCH v3 " Bernd Edlinger
2020-03-17 8:56 ` Kirill Tkhai
2020-03-17 21:53 ` Bernd Edlinger
2020-03-18 12:22 ` Kirill Tkhai
2020-03-18 20:06 ` Bernd Edlinger
2020-03-19 7:13 ` Kirill Tkhai
2020-03-19 7:19 ` Bernd Edlinger
2020-03-19 9:11 ` [PATCH v4 3/5] " Bernd Edlinger
2020-03-19 9:13 ` Bernd Edlinger
2020-03-19 9:19 ` Greg Kroah-Hartman
2020-03-19 9:20 ` Bernd Edlinger
2020-03-21 22:53 ` Bernd Edlinger
2020-03-14 9:12 ` [PATCH 0/2] exec: Fix dead-lock in de_thread with ptrace_attach Bernd Edlinger
2020-03-14 9:12 ` [PATCH 1/2] " Bernd Edlinger
2020-03-14 9:13 ` [PATCH 2/2] doc: Update documentation of ->exec_*_mutex Bernd Edlinger
2020-03-14 9:57 ` [PATCH v2 5/5] exec: Add a exec_update_mutex to replace cred_guard_mutex Bernd Edlinger
2020-03-14 10:02 ` Bernd Edlinger
2020-03-17 8:58 ` Kirill Tkhai
2020-03-09 13:58 ` [PATCH 0/5] Infrastructure to allow fixing exec deadlocks Bernd Edlinger
2020-03-03 16:50 ` [PATCHv5] exec: Fix a deadlock in ptrace Christian Brauner
2020-03-02 12:28 ` [PATCHv2] " Oleg Nesterov
2020-03-02 15:56 ` Bernd Edlinger
2020-03-02 7:47 ` [PATCH] " Christian Brauner
2020-03-02 7:48 ` Christian Brauner
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