Re: [PATCH v2 00/11] tty: Fix buffer work access-after-free

From: Sasha Levin
Date: Wed Dec 19 2012 - 15:38:57 EST


On Tue, Dec 18, 2012 at 11:48 AM, Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> wrote:
> On Tue, 2012-12-18 at 10:44 -0500, Sasha Levin wrote:
>> I'm still seeing that warning with the new patch series:
>>
>> [ 549.561769] ------------[ cut here ]------------
>> [ 549.598755] WARNING: at drivers/tty/n_tty.c:160 n_tty_set_room+0xff/0x130()
>> [ 549.604058] scheduling buffer work for halted ldisc
>> [ 549.607741] Pid: 9417, comm: trinity-child28 Tainted: G D W
>> 3.7.0-next-20121217-sasha-00023-g8689ef9 #219
>> [ 549.652580] Call Trace:
>> [ 549.662754] [<ffffffff81c432cf>] ? n_tty_set_room+0xff/0x130
>> [ 549.665458] [<ffffffff8110cae7>] warn_slowpath_common+0x87/0xb0
>> [ 549.668257] [<ffffffff8110cb71>] warn_slowpath_fmt+0x41/0x50
>> [ 549.671007] [<ffffffff81c432cf>] n_tty_set_room+0xff/0x130
>> [ 549.673268] [<ffffffff81c44597>] reset_buffer_flags+0x137/0x150
>> [ 549.675607] [<ffffffff81c45b71>] n_tty_open+0x131/0x1c0
>
> This is a false-positive warning that means I need to refine the warning
> condition to not include this code path.
>
> Thanks again.

I'm really having a hard time doing any fuzzing after applying this
patch. I'm not sure it's related directly, but
the ldisc hangup lockup happens quite quickly and every time, so I
can't really get any good fuzzing done.

I'm not saying that this patch series is causing it, just saying that
I can't really test it at this point due to
that other lockup.


Thanks,
Sasha
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