From: Eric Sandeen <sandeen@sandeen.net>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>,
Dave Chinner <david@fromorbit.com>,
syzbot <syzbot+84a67953651a971809ba@syzkaller.appspotmail.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-xfs@vger.kernel.org,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
"Theodore Ts'o" <tytso@mit.edu>,
syzkaller <syzkaller@googlegroups.com>
Subject: Re: WARNING: bad unlock balance in xfs_iunlock
Date: Tue, 8 May 2018 21:48:54 -0500 [thread overview]
Message-ID: <9adacfed-0de6-cb94-bf14-3e639678a02a@sandeen.net> (raw)
In-Reply-To: <CACT4Y+YNRt5YSrOYKKFUP25jodpK0xeZhysSGoz2UaiGs_Gx=A@mail.gmail.com>
On 5/8/18 2:52 AM, Dmitry Vyukov wrote:
>> Or put another way, how did you arrive at the fs image values in the reproducer,
>> i.e.:
> Currently they are completely random, nobody taught syzkaller about AGFs, etc.
So you just combine a few megabytes of purely random bits out of thin air until
you get something that approximates an xfs filesystem? Google must have more
computing power than I was aware of.
-Eric
>> oid loop()
>> {
>> memcpy((void*)0x20000000, "xfs", 4);
>> memcpy((void*)0x20000100, "./file0", 8);
>> *(uint64_t*)0x20000200 = 0x20010000;
>> memcpy((void*)0x20010000,
>> "\x58\x46\x53\x42\x00\x00\x10\x00\x00\x00\x00\x00\x00\x00\x10\x00\x00"
>> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x9f\x98"
>> "\x99\xff\xcb\xa1\x4e\xe6\xad\x52\x08\x20\x67\x09\xed\x75\x00\x00\x00"
>> "\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x35\xe0\x00\x00\x00\x00"
>> "\x00\x00\x35\xe1\x00\x00\x00\x00\x00\x00\x35\xe2\x00\x00\x00\x01\x00"
>> "\x00\x10\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x03\x55\xb4\xa4"
>> "\x02\x00\x01\x00\x00\x10\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
>> "\x00\x0c\x09\x08\x04\x0c\x00\x00\x19\x00\x00\x00\x00\x00\x00\x00\x40"
>> "\x00\x00\x00\x00\x00\x00\x00\x3d\x00\x00\x00\x00\x00\x00\x0c\xa3\x00"
>> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
>> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00"
>> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x02\x02",
>> 204);
>>
>> ...
>>
>> The in-memory xfs filesystem it constructs is damaged, is that an intentional
>> part of the fuzzing during the test?
> Yes, invalid inputs is part of testing.
next prev parent reply other threads:[~2018-05-09 2:48 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-03 2:01 WARNING: bad unlock balance in xfs_iunlock syzbot
2018-04-03 4:38 ` Dave Chinner
2018-04-05 18:54 ` Dmitry Vyukov
2018-04-05 21:38 ` Dave Chinner
2018-04-06 16:10 ` Darrick J. Wong
2018-04-13 10:03 ` Dmitry Vyukov
2018-04-16 19:22 ` Eric Sandeen
2018-04-30 13:23 ` Dmitry Vyukov
2018-04-30 13:49 ` Eric Sandeen
2018-04-30 14:02 ` Dmitry Vyukov
2018-04-30 15:14 ` Eric Sandeen
2018-05-02 9:54 ` Jan Tulak
2018-05-08 7:52 ` Dmitry Vyukov
2018-05-09 2:48 ` Eric Sandeen [this message]
2018-05-09 8:43 ` Dmitry Vyukov
2018-05-09 23:22 ` Dave Chinner
2018-05-11 8:59 ` Dmitry Vyukov
2018-05-12 1:16 ` Dave Chinner
2018-05-08 7:54 ` Dmitry Vyukov
2018-04-30 13:24 ` Dmitry Vyukov
2018-05-01 22:51 ` Dave Chinner
2018-05-08 7:56 ` Dmitry Vyukov
2018-05-09 0:50 ` Dave Chinner
2018-05-09 2:37 ` Eric Biggers
2018-05-09 3:32 ` Eric Sandeen
2018-05-09 13:55 ` Theodore Y. Ts'o
2018-05-09 14:13 ` Dmitry Vyukov
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