WARNING: bad unlock balance detected! (3)

WARNING: bad unlock balance detected! (3)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    40e196a906d9 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12a49614c00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7132344728e7ec3f
dashboard link: https://syzkaller.appspot.com/bug?extid=f3e3434787332dfc1c47
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
userspace arch: i386
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13a18ed4c00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+f3e3434787332dfc1c47@syzkaller.appspotmail.com

Enabling of bearer <udp:
yz1> rejected, already enabled
=====================================
Enabling of bearer <udp:
yz1> rejected, already enabled
WARNING: bad unlock balance detected!
5.0.0-rc7+ #80 Not tainted
-------------------------------------
kworker/1:1/22 is trying to release lock (
==================================================================
BUG: KASAN: slab-out-of-bounds in print_unlock_imbalance_bug  
kernel/locking/lockdep.c:3383 [inline]
BUG: KASAN: slab-out-of-bounds in  
print_unlock_imbalance_bug.cold+0x97/0x123 kernel/locking/lockdep.c:3368
Read of size 8 at addr ffff888216be498c by task kworker/1:1/22
Enabling of bearer <udp:
yz1> rejected, already enabled

CPU: 1 PID: 22 Comm: kworker/1:1 Not tainted 5.0.0-rc7+ #80
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue:  addrconf_dad_work (ipv6_addrconf)
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x172/0x1f0 lib/dump_stack.c:113
  print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
  kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135
  print_unlock_imbalance_bug kernel/locking/lockdep.c:3383 [inline]
  print_unlock_imbalance_bug.cold+0x97/0x123 kernel/locking/lockdep.c:3368
  __lock_release kernel/locking/lockdep.c:3601 [inline]
  lock_release+0x67e/0xa00 kernel/locking/lockdep.c:3860
  process_one_work+0xa47/0x1790 kernel/workqueue.c:2180
  worker_thread+0x98/0xe40 kernel/workqueue.c:2319
  kthread+0x357/0x430 kernel/kthread.c:246
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Allocated by task 1:
  save_stack+0x45/0xd0 mm/kasan/common.c:73
  set_track mm/kasan/common.c:85 [inline]
  __kasan_kmalloc mm/kasan/common.c:496 [inline]
  __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
  kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
  kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
  kmalloc include/linux/slab.h:545 [inline]
  kzalloc include/linux/slab.h:740 [inline]
  __alloc_workqueue_key+0x79c/0xe00 kernel/workqueue.c:4099
  addrconf_init+0x9a/0x3b1 net/ipv6/addrconf.c:6906
  inet6_init+0x36c/0x6e1 net/ipv6/af_inet6.c:1022
  do_one_initcall+0x109/0x796 init/main.c:887
  do_initcall_level init/main.c:955 [inline]
  do_initcalls init/main.c:963 [inline]
  do_basic_setup init/main.c:981 [inline]
  kernel_init_freeable+0x4da/0x5c9 init/main.c:1136
  kernel_init+0x12/0x1c5 init/main.c:1054
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff888216be4780
  which belongs to the cache kmalloc-512 of size 512
The buggy address is located 12 bytes to the right of
  512-byte region [ffff888216be4780, ffff888216be4980)
The buggy address belongs to the page:
page:ffffea00085af900 count:1 mapcount:0 mapping:ffff88812c3f0940  
index:0xffff888216be4280
flags: 0x6fffc0000000200(slab)
raw: 06fffc0000000200 ffffea0008581008 ffffea0008597888 ffff88812c3f0940
raw: ffff888216be4280 ffff888216be4000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff888216be4880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff888216be4900: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
> ffff888216be4980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                       ^
  ffff888216be4a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff888216be4a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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Re: WARNING: bad unlock balance detected! (3)

[syzbot]

syzbot has bisected this bug to:

commit ec01fb69ac8034ad6e839b31f9df167a110f868b
Author: Jerome Brunet <jbrunet@baylibre.com>
Date:   Wed Jan 16 17:59:47 2019 +0000

     arm64: dts: meson: s400: fix emmc maximum rate

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10afb7cf200000
start commit:   065b6c4c Merge tag 'devicetree-for-5.1' of git://git.kerne..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=12afb7cf200000
console output: https://syzkaller.appspot.com/x/log.txt?x=14afb7cf200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ea4067c9a08ae046
dashboard link: https://syzkaller.appspot.com/bug?extid=f3e3434787332dfc1c47
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12a10577200000

Reported-by: syzbot+f3e3434787332dfc1c47@syzkaller.appspotmail.com
Fixes: ec01fb69ac80 ("arm64: dts: meson: s400: fix emmc maximum rate")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: WARNING: bad unlock balance detected! (3)

[Jerome Brunet]

On Sat, 2019-03-23 at 07:14 -0700, syzbot wrote:
> syzbot has bisected this bug to:
> 
> commit ec01fb69ac8034ad6e839b31f9df167a110f868b
> Author: Jerome Brunet <jbrunet@baylibre.com>
> Date:   Wed Jan 16 17:59:47 2019 +0000
> 
>      arm64: dts: meson: s400: fix emmc maximum rate
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10afb7cf200000
> start commit:   065b6c4c Merge tag 'devicetree-for-5.1' of git://git.kerne..
> git tree:       upstream
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=12afb7cf200000
> console output: https://syzkaller.appspot.com/x/log.txt?x=14afb7cf200000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=ea4067c9a08ae046
> dashboard link: https://syzkaller.appspot.com/bug?extid=f3e3434787332dfc1c47
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12a10577200000
> 
> Reported-by: syzbot+f3e3434787332dfc1c47@syzkaller.appspotmail.com
> Fixes: ec01fb69ac80 ("arm64: dts: meson: s400: fix emmc maximum rate")
> 
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Hi David,

I'm not sure I understand what the problem reported is but I don't think a DT
patch could be the cause of a locking issue on x86.

If I missed something, feel free to let me know.

Cheers
Jerome

Re: WARNING: bad unlock balance detected! (3)

[Dmitry Vyukov]

On Mon, Mar 25, 2019 at 12:54 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
>
> On Sat, 2019-03-23 at 07:14 -0700, syzbot wrote:
> > syzbot has bisected this bug to:
> >
> > commit ec01fb69ac8034ad6e839b31f9df167a110f868b
> > Author: Jerome Brunet <jbrunet@baylibre.com>
> > Date:   Wed Jan 16 17:59:47 2019 +0000
> >
> >      arm64: dts: meson: s400: fix emmc maximum rate
> >
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10afb7cf200000
> > start commit:   065b6c4c Merge tag 'devicetree-for-5.1' of git://git.kerne..
> > git tree:       upstream
> > final crash:    https://syzkaller.appspot.com/x/report.txt?x=12afb7cf200000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=14afb7cf200000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=ea4067c9a08ae046
> > dashboard link: https://syzkaller.appspot.com/bug?extid=f3e3434787332dfc1c47
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12a10577200000
> >
> > Reported-by: syzbot+f3e3434787332dfc1c47@syzkaller.appspotmail.com
> > Fixes: ec01fb69ac80 ("arm64: dts: meson: s400: fix emmc maximum rate")
> >
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>
> Hi David,
>
> I'm not sure I understand what the problem reported is but I don't think a DT
> patch could be the cause of a locking issue on x86.
>
> If I missed something, feel free to let me know.

Hi Jerome,

I think you are right. It seems that other unrelated kernel bugs have
diverged bisection into the wrong direction.