All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+61ffbb75d30176841f76@syzkaller.appspotmail.com>
To: bristot@redhat.com, kuba@kernel.org,
	linux-kernel@vger.kernel.org, mingo@kernel.org,
	peterz@infradead.org, simon.horman@netronome.com,
	syzkaller-bugs@googlegroups.com
Subject: possible deadlock in __static_key_slow_dec
Date: Thu, 05 Mar 2020 09:35:10 -0800	[thread overview]
Message-ID: <0000000000006f20e205a01ef5e1@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    63623fd4 Merge tag 'for-linus' of git://git.kernel.org/pub..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=154474f9e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5d2e033af114153f
dashboard link: https://syzkaller.appspot.com/bug?extid=61ffbb75d30176841f76
compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14f0efa1e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=119cf3b5e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+61ffbb75d30176841f76@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
5.6.0-rc3-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor374/8758 is trying to acquire lock:
ffffffff892c9f18 (cpu_hotplug_lock.rw_sem){++++}, at: __static_key_slow_dec+0x14/0x90 kernel/jump_label.c:254

but task is already holding lock:
ffff88808438c7d8 (&mm->mmap_sem#2){++++}, at: vm_mmap_pgoff+0xf6/0x1d0 mm/util.c:504

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&mm->mmap_sem#2){++++}:
       lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484
       down_write+0x57/0x140 kernel/locking/rwsem.c:1534
       mpol_rebind_mm+0x37/0x210 mm/mempolicy.c:382
       cpuset_attach+0x35f/0x4c0 kernel/cgroup/cpuset.c:2203
       cgroup_migrate_execute+0x7ac/0xff0 kernel/cgroup/cgroup.c:2445
       cgroup_migrate+0x181/0x190 kernel/cgroup/cgroup.c:2701
       cgroup_attach_task+0x786/0xa10 kernel/cgroup/cgroup.c:2738
       __cgroup1_procs_write+0x257/0x390 kernel/cgroup/cgroup-v1.c:521
       cgroup1_procs_write+0x2a/0x40 kernel/cgroup/cgroup-v1.c:534
       cgroup_file_write+0x223/0x5f0 kernel/cgroup/cgroup.c:3695
       kernfs_fop_write+0x3f0/0x4f0 fs/kernfs/file.c:315
       __vfs_write+0xb8/0x740 fs/read_write.c:494
       vfs_write+0x270/0x580 fs/read_write.c:558
       ksys_write+0x117/0x220 fs/read_write.c:611
       __do_sys_write fs/read_write.c:623 [inline]
       __se_sys_write fs/read_write.c:620 [inline]
       __x64_sys_write+0x7b/0x90 fs/read_write.c:620
       do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #1 (&cpuset_rwsem){++++}:
       lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484
       percpu_down_read include/linux/percpu-rwsem.h:40 [inline]
       cpuset_read_lock+0x3e/0x130 kernel/cgroup/cpuset.c:340
       __sched_setscheduler+0x624/0x1b00 kernel/sched/core.c:4869
       _sched_setscheduler kernel/sched/core.c:5041 [inline]
       sched_setscheduler_nocheck+0x125/0x240 kernel/sched/core.c:5087
       __kthread_create_on_node+0x2eb/0x3b0 kernel/kthread.c:349
       kthread_create_on_node+0x72/0xa0 kernel/kthread.c:388
       create_worker+0x396/0x890 kernel/workqueue.c:1924
       workqueue_prepare_cpu+0x98/0x110 kernel/workqueue.c:5024
       cpuhp_invoke_callback+0x4c9/0x8b0 kernel/cpu.c:172
       cpuhp_up_callbacks kernel/cpu.c:599 [inline]
       _cpu_up+0x307/0x550 kernel/cpu.c:1165
       do_cpu_up+0x159/0x1a0 kernel/cpu.c:1200
       cpu_up+0x18/0x20 kernel/cpu.c:1208
       smp_init+0x107/0x29a kernel/smp.c:604
       kernel_init_freeable+0x2f2/0x429 init/main.c:1432
       kernel_init+0x11/0x290 init/main.c:1346
       ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

-> #0 (cpu_hotplug_lock.rw_sem){++++}:
       check_prev_add kernel/locking/lockdep.c:2475 [inline]
       check_prevs_add kernel/locking/lockdep.c:2580 [inline]
       validate_chain+0x1507/0x7be0 kernel/locking/lockdep.c:2970
       __lock_acquire+0xc5a/0x1bc0 kernel/locking/lockdep.c:3954
       lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484
       percpu_down_read include/linux/percpu-rwsem.h:40 [inline]
       cpus_read_lock+0x3e/0x130 kernel/cpu.c:292
       __static_key_slow_dec+0x14/0x90 kernel/jump_label.c:254
       static_key_slow_dec+0x50/0xa0 kernel/jump_label.c:270
       sw_perf_event_destroy+0x78/0x170 kernel/events/core.c:8840
       _free_event+0x825/0xdc0 kernel/events/core.c:4616
       put_event kernel/events/core.c:4710 [inline]
       perf_mmap_close+0xc04/0xea0 kernel/events/core.c:5754
       remove_vma mm/mmap.c:177 [inline]
       remove_vma_list mm/mmap.c:2568 [inline]
       __do_munmap+0x1006/0x14b0 mm/mmap.c:2812
       do_munmap mm/mmap.c:2820 [inline]
       mmap_region+0x8c8/0x1c40 mm/mmap.c:1713
       do_mmap+0xa8f/0x1100 mm/mmap.c:1543
       do_mmap_pgoff include/linux/mm.h:2334 [inline]
       vm_mmap_pgoff+0x13d/0x1d0 mm/util.c:506
       ksys_mmap_pgoff+0x45b/0x540 mm/mmap.c:1593
       __do_sys_mmap arch/x86/kernel/sys_x86_64.c:99 [inline]
       __se_sys_mmap arch/x86/kernel/sys_x86_64.c:90 [inline]
       __x64_sys_mmap+0x103/0x120 arch/x86/kernel/sys_x86_64.c:90
       do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

Chain exists of:
  cpu_hotplug_lock.rw_sem --> &cpuset_rwsem --> &mm->mmap_sem#2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&mm->mmap_sem#2);
                               lock(&cpuset_rwsem);
                               lock(&mm->mmap_sem#2);
  lock(cpu_hotplug_lock.rw_sem);

 *** DEADLOCK ***

1 lock held by syz-executor374/8758:
 #0: ffff88808438c7d8 (&mm->mmap_sem#2){++++}, at: vm_mmap_pgoff+0xf6/0x1d0 mm/util.c:504

stack backtrace:
CPU: 1 PID: 8758 Comm: syz-executor374 Not tainted 5.6.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 print_circular_bug+0xc3f/0xe70 kernel/locking/lockdep.c:1684
 check_noncircular+0x206/0x3a0 kernel/locking/lockdep.c:1808
 check_prev_add kernel/locking/lockdep.c:2475 [inline]
 check_prevs_add kernel/locking/lockdep.c:2580 [inline]
 validate_chain+0x1507/0x7be0 kernel/locking/lockdep.c:2970
 __lock_acquire+0xc5a/0x1bc0 kernel/locking/lockdep.c:3954
 lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484
 percpu_down_read include/linux/percpu-rwsem.h:40 [inline]
 cpus_read_lock+0x3e/0x130 kernel/cpu.c:292
 __static_key_slow_dec+0x14/0x90 kernel/jump_label.c:254
 static_key_slow_dec+0x50/0xa0 kernel/jump_label.c:270
 sw_perf_event_destroy+0x78/0x170 kernel/events/core.c:8840
 _free_event+0x825/0xdc0 kernel/events/core.c:4616
 put_event kernel/events/core.c:4710 [inline]
 perf_mmap_close+0xc04/0xea0 kernel/events/core.c:5754
 remove_vma mm/mmap.c:177 [inline]
 remove_vma_list mm/mmap.c:2568 [inline]
 __do_munmap+0x1006/0x14b0 mm/mmap.c:2812
 do_munmap mm/mmap.c:2820 [inline]
 mmap_region+0x8c8/0x1c40 mm/mmap.c:1713
 do_mmap+0xa8f/0x1100 mm/mmap.c:1543
 do_mmap_pgoff include/linux/mm.h:2334 [inline]
 vm_mmap_pgoff+0x13d/0x1d0 mm/util.c:506
 ksys_mmap_pgoff+0x45b/0x540 mm/mmap.c:1593
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:99 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:90 [inline]
 __x64_sys_mmap+0x103/0x120 arch/x86/kernel/sys_x86_64.c:90
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4473b9
Code: e8 4c bb 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f0272a71da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 00000000004473b9
RDX: 0000000000000000 RSI: 0000000000003000 RDI: 0000000020ffd000
RBP: 00000000006dcc30 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 00000000006dcc3c
R13: 00007ffcae9c6f0f R14: 00007f0272a729c0 R15: 0000000000000000


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

             reply	other threads:[~2020-03-05 17:35 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-05 17:35 syzbot [this message]
2020-03-05 20:24 ` possible deadlock in __static_key_slow_dec Peter Zijlstra
2020-03-09  3:09 ` syzbot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=0000000000006f20e205a01ef5e1@google.com \
    --to=syzbot+61ffbb75d30176841f76@syzkaller.appspotmail.com \
    --cc=bristot@redhat.com \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=simon.horman@netronome.com \
    --cc=syzkaller-bugs@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.