All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dmitry Vyukov <dvyukov@google.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	syzkaller <syzkaller@googlegroups.com>
Subject: Re: perf: use-after-free in perf_release
Date: Tue, 7 Mar 2017 15:17:34 +0100	[thread overview]
Message-ID: <CACT4Y+bzNOrMHmfP_cv3Jzaqs0zB3qHY9eu0y4JdKvVw0mgveA@mail.gmail.com> (raw)
In-Reply-To: <20170307140414.GA31678@redhat.com>

On Tue, Mar 7, 2017 at 3:04 PM, Oleg Nesterov <oleg@redhat.com> wrote:
> On 03/06, Peter Zijlstra wrote:
>>
>> and this is a failed fork().
>>
>>
>> However, inherited events don't have a filedesc to fput(), and
>> similarly, a task that fails for has never been visible to attach a perf
>> event to because it never hits the pid-hash.
>
> Yes, it is not visible to find_task_by_vpid() until copy_process() does
> attach_pid(PIDTYPE_PID), and copy_process() can't fail after that.


I would what is that that is failed in copy_process. Could it be
perf_event_init_task itself? Maybe it leaves a pointer to p in some
shared state on some error conditions?

  reply	other threads:[~2017-03-07 14:27 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-06  9:57 perf: use-after-free in perf_release Dmitry Vyukov
2017-03-06 12:13 ` Peter Zijlstra
2017-03-06 12:17   ` Dmitry Vyukov
2017-03-06 12:23     ` Peter Zijlstra
2017-03-06 12:27       ` Dmitry Vyukov
2017-03-06 12:47         ` Peter Zijlstra
2017-03-06 13:14 ` Peter Zijlstra
2017-03-06 13:34   ` Dmitry Vyukov
2017-03-07  9:08     ` Peter Zijlstra
2017-03-07  9:26       ` Dmitry Vyukov
2017-03-07  9:37         ` Peter Zijlstra
2017-03-07  9:43           ` Dmitry Vyukov
2017-03-07 10:00             ` Peter Zijlstra
2017-03-07 13:16   ` Peter Zijlstra
2017-03-07 13:27     ` Peter Zijlstra
2017-03-07 14:04   ` Oleg Nesterov
2017-03-07 14:17     ` Dmitry Vyukov [this message]
2017-03-07 16:51       ` Oleg Nesterov
2017-03-07 17:29         ` Peter Zijlstra
2017-03-14 12:55         ` Peter Zijlstra
2017-03-14 13:24           ` Oleg Nesterov
2017-03-14 13:47             ` Peter Zijlstra
2017-03-14 14:03           ` Oleg Nesterov
2017-03-14 14:07             ` Peter Zijlstra
2017-03-14 14:30               ` Oleg Nesterov
2017-03-14 15:02                 ` Peter Zijlstra
2017-03-14 15:07                   ` Peter Zijlstra
2017-03-14 15:37                     ` Oleg Nesterov
2017-03-14 15:46                       ` Peter Zijlstra
2017-03-14 15:19                   ` Oleg Nesterov
2017-03-14 15:26                     ` Peter Zijlstra
2017-03-14 15:59                       ` Peter Zijlstra
2017-03-15 16:43                         ` Oleg Nesterov
2017-03-16 12:05                           ` Peter Zijlstra
2017-03-16 13:57                           ` Peter Zijlstra
2017-03-16 16:41                             ` Oleg Nesterov
2017-03-16 12:47 [PATCH 0/4] perf patches Peter Zijlstra
2017-03-16 12:47 ` [PATCH 1/4] perf: Fix use-after-free in perf_release() Peter Zijlstra
2017-03-16 15:19   ` [tip:perf/urgent] perf/core: " tip-bot for Peter Zijlstra
2017-03-16 12:47 ` [PATCH 2/4] perf: Fix event inheritance on fork() Peter Zijlstra
2017-03-16 15:19   ` [tip:perf/urgent] perf/core: " tip-bot for Peter Zijlstra
2017-03-16 12:47 ` [PATCH 3/4] perf: Simplify perf_event_free_task() Peter Zijlstra
2017-03-16 15:20   ` [tip:perf/urgent] perf/core: " tip-bot for Peter Zijlstra
2017-03-16 12:47 ` [PATCH 4/4] perf: Better explain the inherit magic Peter Zijlstra
2017-03-16 15:21   ` [tip:perf/urgent] perf/core: " tip-bot for Peter Zijlstra
2017-03-16 13:20 ` [PATCH 0/4] perf patches Ingo Molnar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CACT4Y+bzNOrMHmfP_cv3Jzaqs0zB3qHY9eu0y4JdKvVw0mgveA@mail.gmail.com \
    --to=dvyukov@google.com \
    --cc=acme@kernel.org \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=mingo@redhat.com \
    --cc=oleg@redhat.com \
    --cc=peterz@infradead.org \
    --cc=syzkaller@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.