Re: perf: use-after-free in perf_release

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: perf: use-after-free in perf_release
Date	2017-03-07 12:50 +0100
Message-ID	<tilMR-6W3-5@gated-at.bofh.it> (permalink)
References	(2 earlier) <ti11M-rk-7@gated-at.bofh.it> <tijBo-5s7-19@gated-at.bofh.it> <tijBo-5s7-17@gated-at.bofh.it> <tijUK-5z1-5@gated-at.bofh.it> <tijUK-5z1-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Tue, Mar 07, 2017 at 10:43:32AM +0100, Dmitry Vyukov wrote:

> An old syzkaller may not understand part of syscalls in the program
> and silently drop them, you need a new one.

That's yucky semantics, better to at least warn on that occasion.

> Here is a straightforward conversion of the syzkaller program to C
> (with/without namespace sandbox):
> 
> https://gist.githubusercontent.com/dvyukov/b6540bed50b7da1dff3d7373ba570c77/raw/fd5f2f3aaa52b70b2bb9f114cf8a3226d8a30960/gistfile1.txt
> https://gist.githubusercontent.com/dvyukov/dbd8ec38bcb50df4bdc95210d4247b09/raw/f9cbb5e17cd4ff4a7a7881c97dea7d6cd6dd8bf1/gistfile1.txt

Thanks!

> That's also with -procs=10, you can change number of procs in main funciton.
> 
> But I wasn't able to reproduce the crash using these programs (neither
> the syzkaller program), that's why I did not provide it all initially.

Right, I'll run them while at the same time trying to see what it is
they're doing to find clues.

Thread

perf: use-after-free in perf_release Dmitry Vyukov <dvyukov@google.com> - 2017-03-06 11:00 +0100
  Re: perf: use-after-free in perf_release Peter Zijlstra <peterz@infradead.org> - 2017-03-06 13:20 +0100
    Re: perf: use-after-free in perf_release Dmitry Vyukov <dvyukov@google.com> - 2017-03-06 13:20 +0100
      Re: perf: use-after-free in perf_release Peter Zijlstra <peterz@infradead.org> - 2017-03-06 13:30 +0100
        Re: perf: use-after-free in perf_release Dmitry Vyukov <dvyukov@google.com> - 2017-03-06 13:40 +0100
          Re: perf: use-after-free in perf_release Peter Zijlstra <peterz@infradead.org> - 2017-03-06 13:50 +0100
  Re: perf: use-after-free in perf_release Peter Zijlstra <peterz@infradead.org> - 2017-03-06 14:30 +0100
    Re: perf: use-after-free in perf_release Dmitry Vyukov <dvyukov@google.com> - 2017-03-06 14:40 +0100
      Re: perf: use-after-free in perf_release Dmitry Vyukov <dvyukov@google.com> - 2017-03-07 10:30 +0100
        Re: perf: use-after-free in perf_release Dmitry Vyukov <dvyukov@google.com> - 2017-03-07 10:50 +0100
          Re: perf: use-after-free in perf_release Peter Zijlstra <peterz@infradead.org> - 2017-03-07 12:50 +0100
        Re: perf: use-after-free in perf_release Peter Zijlstra <peterz@infradead.org> - 2017-03-07 11:40 +0100
      Re: perf: use-after-free in perf_release Peter Zijlstra <peterz@infradead.org> - 2017-03-07 10:50 +0100
    Re: perf: use-after-free in perf_release Peter Zijlstra <peterz@infradead.org> - 2017-03-07 14:20 +0100
      Re: perf: use-after-free in perf_release Peter Zijlstra <peterz@infradead.org> - 2017-03-07 15:10 +0100
    Re: perf: use-after-free in perf_release Oleg Nesterov <oleg@redhat.com> - 2017-03-07 15:10 +0100
      Re: perf: use-after-free in perf_release Dmitry Vyukov <dvyukov@google.com> - 2017-03-07 15:30 +0100
        Re: perf: use-after-free in perf_release Peter Zijlstra <peterz@infradead.org> - 2017-03-07 18:40 +0100
        Re: perf: use-after-free in perf_release Oleg Nesterov <oleg@redhat.com> - 2017-03-07 18:50 +0100

csiph-web