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Date:   Mon, 02 Apr 2018 19:01:01 -0700
Message-ID: <001a1148578c10e4700568e814eb@google.com>
Subject: WARNING in up_write
From:   syzbot <syzbot+dc5ab2babdf22ca091af@syzkaller.appspotmail.com>
To:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk
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Sender: linux-kernel-owner@vger.kernel.org
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Hello,

syzbot hit the following crash on upstream commit
86bbbebac1933e6e95e8234c4f7d220c5ddd38bc (Mon Apr 2 18:47:07 2018 +0000)
Merge branch 'ras-core-for-linus' of  
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
syzbot dashboard link:  
https://syzkaller.appspot.com/bug?extid=dc5ab2babdf22ca091af

So far this crash happened 8 times on upstream.
C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5688491102961664
syzkaller reproducer:  
https://syzkaller.appspot.com/x/repro.syz?id=5709211904245760
Raw console output:  
https://syzkaller.appspot.com/x/log.txt?id=5720789257027584
Kernel config:  
https://syzkaller.appspot.com/x/.config?id=6801295859785128502
compiler: gcc (GCC) 7.1.1 20170620

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+dc5ab2babdf22ca091af@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for  
details.
If you forward the report, please keep this part and the footer.

EXT4-fs (sda1): shut down requested (0)
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(sem->owner != get_current())
WARNING: CPU: 1 PID: 4441 at kernel/locking/rwsem.c:133  
up_write+0x1cc/0x210 kernel/locking/rwsem.c:133
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 4441 Comm: syzkaller594909 Not tainted 4.16.0+ #11
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x1a7/0x27d lib/dump_stack.c:53
  panic+0x1f8/0x42c kernel/panic.c:183
  __warn+0x1dc/0x200 kernel/panic.c:547
  report_bug+0x1f4/0x2b0 lib/bug.c:186
  fixup_bug.part.10+0x37/0x80 arch/x86/kernel/traps.c:178
  fixup_bug arch/x86/kernel/traps.c:247 [inline]
  do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296
  do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
  invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986
RIP: 0010:up_write+0x1cc/0x210 kernel/locking/rwsem.c:133
RSP: 0018:ffff8801b349f710 EFLAGS: 00010286
RAX: dffffc0000000008 RBX: ffff8801ccc0ce40 RCX: ffffffff815ae26e
RDX: 0000000000000000 RSI: 1ffff10036693e92 RDI: 1ffff10036693e67
RBP: ffff8801b349f798 R08: fffffbfff10b0659 R09: fffffbfff10b0659
R10: ffff8801b349f708 R11: fffffbfff10b0658 R12: 1ffff10036693ee2
R13: dffffc0000000000 R14: ffff8801b349f770 R15: ffff8801ccc0ce98
  percpu_up_write+0xca/0x110 kernel/locking/percpu-rwsem.c:183
  sb_freeze_unlock fs/super.c:1390 [inline]
  thaw_super+0x1ca/0x260 fs/super.c:1524
  thaw_bdev+0x151/0x180 fs/block_dev.c:555
  ext4_shutdown fs/ext4/ioctl.c:489 [inline]
  ext4_ioctl+0x1f85/0x3e60 fs/ext4/ioctl.c:1048
  vfs_ioctl fs/ioctl.c:46 [inline]
  do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
  SYSC_ioctl fs/ioctl.c:701 [inline]
  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x440109
RSP: 002b:00007fffce185d28 EFLAGS: 00000213 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440109
RDX: 0000000020000100 RSI: 000000008004587d RDI: 0000000000000003
RBP: 00000000006ca018 R08: 000000000000000f R09: 65732f636f72702f
R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401990
R13: 0000000000401a20 R14: 0000000000000000 R15: 0000000000000000
Dumping ftrace buffer:
    (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..


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