From: Vince Weaver <vincent.weaver@maine.edu>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Vince Weaver <vincent.weaver@maine.edu>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [perf] more perf_fuzzer memory corruption
Date: Fri, 2 May 2014 12:43:17 -0400 (EDT) [thread overview]
Message-ID: <alpine.DEB.2.10.1405021230130.22556@vincent-weaver-1.umelst.maine.edu> (raw)
In-Reply-To: <20140502162234.GX11096@twins.programming.kicks-ass.net>
On Fri, 2 May 2014, Peter Zijlstra wrote:
> In principle the vfs file refcounting should be responsible for that.
> But I'll go over it in a bit.
The poll code is ancient and the C-parser in my head really can't handle
it very well.
Anyway for completeness this is the kind of thing I'm seeing.
The poll() manpage isn't very clear about what is supposed to happen if
you poll() on a closed file descriptor.
FD#3 closed
perf_fuzzer-2293 [003] 286.500137: sys_enter: NR 3 (3, 7fff841b9eac, 0, 22, 7ff17078110c, 7ff170781120)
Child killed:
perf_fuzzer-2293 [003] 286.505587: sys_exit: NR 62 = 0
Poll started, seems to have freed fd #3 as an argument:
perf_fuzzer-2293 [003] 286.505703: sys_enter: NR 7 (7fff841b9b00, 55, 3, 40e3e3, 7ff1707810dc, 7ff170781120)
(child is still closing out at this point)
Event freed:
<...>-2701 [004] 286.505904: bprint: _free_event: freeing with 0 refs; ptr=0x0xffff8800ce88e000
fd#3 is still being polled despite the event being completely gone now:
perf_fuzzer-2293 [003] 286.508846: bprint: do_sys_poll: VMW: poll 3
perf_fuzzer-2293 [003] 286.508847: function: perf_poll
perf_fuzzer-2293 [003] 286.508848: bprint: do_sys_poll: VMW: poll 3
perf_fuzzer-2293 [003] 286.508849: function: perf_poll
perf_fuzzer-2293 [003] 286.508850: bprint: do_sys_poll: VMW: poll 3
perf_fuzzer-2293 [003] 286.508846: bprint: do_sys_poll: VMW: poll 3
perf_fuzzer-2293 [003] 286.508847: function: perf_poll
perf_fuzzer-2293 [003] 286.508848: bprint: do_sys_poll: VMW: poll 3
perf_fuzzer-2293 [003] 286.508849: function: perf_poll
perf_fuzzer-2293 [003] 286.508850: bprint: do_sys_poll: VMW: poll 3
perf_fuzzer-2293 [003] 286.508850: function: perf_poll
perf_fuzzer-2293 [003] 286.508851: bprint: do_sys_poll: VMW: poll 12
perf_fuzzer-2293 [003] 286.508850: function: perf_poll
perf_fuzzer-2293 [003] 286.508851: bprint: do_sys_poll: VMW: poll 12
Finally done polling:
perf_fuzzer-2293 [003] 286.509002: sys_exit: NR 7 = 0
next prev parent reply other threads:[~2014-05-02 16:39 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-15 21:37 [perf] more perf_fuzzer memory corruption Vince Weaver
2014-04-15 21:49 ` Thomas Gleixner
2014-04-16 3:21 ` Vince Weaver
2014-04-16 4:18 ` Vince Weaver
2014-04-16 14:15 ` Peter Zijlstra
2014-04-16 17:30 ` Vince Weaver
2014-04-16 17:43 ` Vince Weaver
2014-04-16 17:47 ` Peter Zijlstra
2014-04-17 9:48 ` Ingo Molnar
2014-04-17 11:45 ` Peter Zijlstra
2014-04-17 14:22 ` Ingo Molnar
2014-04-17 14:42 ` Vince Weaver
2014-04-17 14:54 ` Peter Zijlstra
2014-04-17 15:35 ` Vince Weaver
2014-04-18 14:45 ` Vince Weaver
2014-04-18 14:51 ` Vince Weaver
2014-04-18 15:23 ` Peter Zijlstra
2014-04-18 16:59 ` Peter Zijlstra
2014-04-18 17:15 ` Peter Zijlstra
2014-04-23 20:58 ` Vince Weaver
2014-04-25 2:51 ` Vince Weaver
2014-04-28 14:21 ` Vince Weaver
2014-04-28 19:38 ` Vince Weaver
2014-04-29 9:46 ` Peter Zijlstra
2014-04-29 18:21 ` Vince Weaver
2014-04-29 19:01 ` Peter Zijlstra
2014-04-29 20:59 ` Vince Weaver
2014-04-30 18:44 ` Peter Zijlstra
2014-04-30 21:08 ` Vince Weaver
2014-04-30 22:51 ` Thomas Gleixner
2014-05-01 10:26 ` Peter Zijlstra
2014-05-01 11:50 ` Peter Zijlstra
2014-05-01 12:35 ` Thomas Gleixner
2014-05-01 13:12 ` Peter Zijlstra
2014-05-01 13:29 ` Thomas Gleixner
2014-05-01 13:22 ` Vince Weaver
2014-05-01 14:07 ` Vince Weaver
2014-05-01 14:27 ` Vince Weaver
2014-05-01 15:09 ` Peter Zijlstra
2014-05-01 15:50 ` Vince Weaver
2014-05-01 16:31 ` Thomas Gleixner
2014-05-01 17:18 ` Vince Weaver
2014-05-01 18:49 ` Vince Weaver
2014-05-01 21:32 ` Vince Weaver
2014-05-02 11:15 ` Peter Zijlstra
2014-05-02 15:42 ` Peter Zijlstra
2014-05-02 16:22 ` Vince Weaver
2014-05-02 16:22 ` Peter Zijlstra
2014-05-02 16:43 ` Vince Weaver [this message]
2014-05-02 17:27 ` Peter Zijlstra
2014-05-02 17:46 ` Vince Weaver
2014-05-02 19:12 ` Thomas Gleixner
2014-05-02 20:15 ` Vince Weaver
2014-05-02 20:45 ` Thomas Gleixner
2014-05-03 2:32 ` Vince Weaver
2014-05-03 3:02 ` Vince Weaver
2014-05-03 7:33 ` Peter Zijlstra
2014-05-05 9:31 ` Peter Zijlstra
2014-05-05 16:00 ` Vince Weaver
2014-05-05 17:10 ` Vince Weaver
2014-05-05 17:14 ` Peter Zijlstra
2014-05-05 18:47 ` Vince Weaver
2014-05-05 19:36 ` Peter Zijlstra
2014-05-05 19:51 ` Vince Weaver
2014-05-06 1:06 ` Vince Weaver
2014-05-06 16:57 ` Vince Weaver
2014-05-07 16:45 ` Peter Zijlstra
2014-05-08 10:40 ` [tip:perf/core] perf: Fix perf_event_init_context() tip-bot for Peter Zijlstra
2014-05-05 17:29 ` [perf] more perf_fuzzer memory corruption Ingo Molnar
2014-05-06 4:51 ` Vince Weaver
2014-05-06 17:06 ` Vince Weaver
2014-05-07 19:12 ` Ingo Molnar
2014-05-07 19:11 ` Ingo Molnar
2014-05-08 10:40 ` [tip:perf/core] perf: Fix race in removing an event tip-bot for Peter Zijlstra
2014-05-02 17:06 ` [perf] more perf_fuzzer memory corruption Vince Weaver
2014-05-02 17:04 ` Peter Zijlstra
2014-04-29 19:26 ` Steven Rostedt
2014-04-29 8:52 ` Peter Zijlstra
2014-04-29 18:11 ` Vince Weaver
2014-04-29 19:21 ` Steven Rostedt
2014-04-28 17:48 ` Thomas Gleixner
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