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INFO: task hung in blkdev_put (2)

Status: auto-closed as invalid on 2020/07/26 14:38
Reported-by: syzbot+3ef6af1ea092e2380317@syzkaller.appspotmail.com
First crash: 1520d, last: 1482d
▶ ▼ Similar bugs (14)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in blkdev_put (3) fs 1 1453d 1453d 0/26 auto-closed as invalid on 2020/06/25 13:28
android-49 INFO: task hung in blkdev_put (2) 3 1616d 1635d 0/3 auto-closed as invalid on 2020/03/14 12:22
linux-4.19 INFO: task hung in blkdev_put C error 31 600d 1364d 0/1 upstream: reported C repro on 2020/07/23 21:33
upstream INFO: task hung in blkdev_put udf 320 1894d 2321d 0/26 closed as dup on 2018/11/11 08:29
linux-4.14 INFO: task hung in blkdev_put 2 1678d 1828d 0/1 auto-closed as invalid on 2020/01/12 01:56
linux-5.15 INFO: task hung in blkdev_put origin:upstream C error 4 24d 300d 0/3 upstream: reported C repro on 2023/06/23 01:15
linux-4.14 INFO: task hung in blkdev_put (3) C error 16 549d 1326d 0/1 upstream: reported C repro on 2020/08/30 21:52
upstream INFO: task hung in blkdev_put (4) block C done 486 37d 1293d 0/26 upstream: reported C repro on 2020/10/03 13:09
android-49 INFO: task hung in blkdev_put 220 1814d 1831d 0/3 auto-closed as invalid on 2019/10/25 08:47
android-414 INFO: task hung in blkdev_put 119 1600d 1832d 0/1 auto-closed as invalid on 2020/03/30 04:06
android-44 INFO: task hung in blkdev_put 26 1900d 1831d 0/2 auto-closed as invalid on 2019/08/03 02:42
android-44 INFO: task hung in blkdev_put (2) 3 1612d 1689d 0/2 auto-closed as invalid on 2020/03/18 19:27
linux-6.1 INFO: task hung in blkdev_put origin:upstream C 86 4d05h 359d 0/3 upstream: reported C repro on 2023/04/25 09:01
upstream INFO: task hung in blkdev_put (2) fs 2 1607d 1653d 0/26 auto-closed as invalid on 2020/02/22 04:07

Sample crash report:
INFO: task syz-executor.1:30076 blocked for more than 140 seconds.
      Not tainted 4.14.174-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28688 30076   7440 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 blkdev_put+0x27/0x4c0 fs/block_dev.c:1814
 blkdev_close+0x86/0xb0 fs/block_dev.c:1863
 __fput+0x25f/0x790 fs/file_table.c:210
 task_work_run+0x113/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1d6/0x220 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4163e1
RSP: 002b:00007ffeea2bbe00 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00000000004163e1
RDX: 0000000000000000 RSI: 0000000000001bf9 RDI: 0000000000000004
RBP: 0000000000000001 R08: 000000009ab57bf9 R09: 000000009ab57bfd
R10: 00007ffeea2bbee0 R11: 0000000000000293 R12: 000000000076c900
R13: 000000000076c900 R14: 00000000000cf653 R15: 000000000076bf0c
INFO: task syz-executor.1:30084 blocked for more than 140 seconds.
      Not tainted 4.14.174-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28992 30084   7440 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 lo_release+0x1b/0x190 drivers/block/loop.c:1677
 __blkdev_put+0x4ec/0x6a0 fs/block_dev.c:1791
 deactivate_locked_super+0x6c/0xd0 fs/super.c:319
 mount_bdev+0x328/0x370 fs/super.c:1136
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x3c0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x3c9/0x24f0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xa8/0x120 fs/namespace.c:3072
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45f29a
RSP: 002b:00007f95208cba68 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f95208cc6d4 RCX: 000000000045f29a
RDX: 00007f95208cbae0 RSI: 0000000020000380 RDI: 00007f95208cbb00
RBP: 000000000076bf00 R08: 00007f95208cbb40 R09: 00007f95208cbae0
R10: 0000000000000003 R11: 0000000000000206 R12: 00000000ffffffff
R13: 0000000000000beb R14: 00000000004ce0e8 R15: 000000000076bf0c
INFO: task syz-executor.0:30087 blocked for more than 140 seconds.
      Not tainted 4.14.174-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D27520 30087   7437 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 loop_control_ioctl+0x15b/0x2d0 drivers/block/loop.c:2007
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c849
RSP: 002b:00007fe9a7085c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe9a70866d4 RCX: 000000000045c849
RDX: 0000000000000003 RSI: 0000000000004c81 RDI: 0000000000000006
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000003ed R14: 00000000004c6821 R15: 000000000076bf0c
INFO: task syz-executor.3:30086 blocked for more than 140 seconds.
      Not tainted 4.14.174-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D29136 30086   7439 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192
 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:624
 loop_set_status+0xbfc/0x11f0 drivers/block/loop.c:1193
 loop_set_status64+0x92/0xe0 drivers/block/loop.c:1311
 lo_ioctl+0x590/0x1c40 drivers/block/loop.c:1441
 __blkdev_driver_ioctl block/ioctl.c:297 [inline]
 blkdev_ioctl+0x91d/0x17d0 block/ioctl.c:594
 block_ioctl+0xd9/0x120 fs/block_dev.c:1881
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c6b7
RSP: 002b:00007f5d5486d9d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045c6b7
RDX: 00007f5d5486dac0 RSI: 0000000000004c04 RDI: 0000000000000006
RBP: 000000000076bf00 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000202 R12: 00000000ffffffff
R13: 0000000000000c1b R14: 00000000004c1905 R15: 000000000076bf0c
INFO: task syz-executor.4:30092 blocked for more than 140 seconds.
      Not tainted 4.14.174-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D29376 30092   7438 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 lo_open+0x19/0xb0 drivers/block/loop.c:1634
 __blkdev_get+0x2a6/0x10d0 fs/block_dev.c:1472
 blkdev_get+0x84/0x8a0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x732/0xe90 fs/open.c:777
 vfs_open+0x105/0x220 fs/open.c:888
 do_last fs/namei.c:3428 [inline]
 path_openat+0x8ca/0x3c50 fs/namei.c:3569
 do_filp_open+0x18e/0x250 fs/namei.c:3603
 do_sys_open+0x29d/0x3f0 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4165e1
RSP: 002b:00007f42f7c2b9d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f42f7c2c6d4 RCX: 00000000004165e1
RDX: 00007f42f7c2bbba RSI: 0000000000000002 RDI: 00007f42f7c2bbb0
RBP: 000000000076bf00 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c1b R14: 00000000004c1905 R15: 000000000076bf0c
INFO: task blkid:30090 blocked for more than 140 seconds.
      Not tainted 4.14.174-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D29200 30090   7820 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 __blkdev_get+0x131/0x10d0 fs/block_dev.c:1457
 blkdev_get+0x84/0x8a0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x732/0xe90 fs/open.c:777
 vfs_open+0x105/0x220 fs/open.c:888
 do_last fs/namei.c:3428 [inline]
 path_openat+0x8ca/0x3c50 fs/namei.c:3569
 do_filp_open+0x18e/0x250 fs/namei.c:3603
 do_sys_open+0x29d/0x3f0 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f16bd264120
RSP: 002b:00007ffed495f978 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f16bd264120
RDX: 00007ffed4961f40 RSI: 0000000000000000 RDI: 00007ffed4961f40
RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001868030
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005
INFO: task blkid:30095 blocked for more than 140 seconds.
      Not tainted 4.14.174-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D29200 30095   7035 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 lo_open+0x19/0xb0 drivers/block/loop.c:1634
 __blkdev_get+0xa70/0x10d0 fs/block_dev.c:1537
 blkdev_get+0x84/0x8a0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x732/0xe90 fs/open.c:777
 vfs_open+0x105/0x220 fs/open.c:888
 do_last fs/namei.c:3428 [inline]
 path_openat+0x8ca/0x3c50 fs/namei.c:3569
 do_filp_open+0x18e/0x250 fs/namei.c:3603
 do_sys_open+0x29d/0x3f0 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f30f1560120
RSP: 002b:00007ffc6c7c7758 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f30f1560120
RDX: 00007ffc6c7c9f40 RSI: 0000000000000000 RDI: 00007ffc6c7c9f40
RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000147f030
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005
INFO: task blkid:30096 blocked for more than 140 seconds.
      Not tainted 4.14.174-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D28864 30096   7399 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 __blkdev_get+0x131/0x10d0 fs/block_dev.c:1457
 blkdev_get+0x84/0x8a0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x732/0xe90 fs/open.c:777
 vfs_open+0x105/0x220 fs/open.c:888
 do_last fs/namei.c:3428 [inline]
 path_openat+0x8ca/0x3c50 fs/namei.c:3569
 do_filp_open+0x18e/0x250 fs/namei.c:3603
 do_sys_open+0x29d/0x3f0 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f3f5f146120
RSP: 002b:00007ffca2eff718 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3f5f146120
RDX: 00007ffca2f00f40 RSI: 0000000000000000 RDI: 00007ffca2f00f40
RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000015cd030
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005

Showing all locks held in the system:
1 lock held by khungtaskd/1058:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff81465b93>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544
2 locks held by getty/7392:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7393:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7394:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7395:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7396:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7397:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
2 locks held by getty/7398:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff833adad2>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff833a1714>] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.1/30076:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<ffffffff8197dd57>] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814
2 locks held by syz-executor.1/30084:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<ffffffff8197c65e>] __blkdev_put+0x9e/0x6a0 fs/block_dev.c:1778
 #1:  (loop_index_mutex){+.+.}, at: [<ffffffff839d2fab>] lo_release+0x1b/0x190 drivers/block/loop.c:1677
2 locks held by syz-executor.0/30087:
 #0:  (loop_index_mutex){+.+.}, at: [<ffffffff839d4731>] loop_control_ioctl+0x61/0x2d0 drivers/block/loop.c:1993
 #1:  (&lo->lo_ctl_mutex#2){+.+.}, at: [<ffffffff839d482b>] loop_control_ioctl+0x15b/0x2d0 drivers/block/loop.c:2007
2 locks held by syz-executor.3/30086:
 #0:  (&lo->lo_ctl_mutex/1){+.+.}, at: [<ffffffff839d4b87>] lo_ioctl+0x87/0x1c40 drivers/block/loop.c:1414
 #1:  (&bdev->bd_mutex){+.+.}, at: [<ffffffff82f0bf6b>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192
2 locks held by syz-executor.4/30092:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<ffffffff8197cd91>] __blkdev_get+0x131/0x10d0 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<ffffffff839ce579>] lo_open+0x19/0xb0 drivers/block/loop.c:1634
1 lock held by blkid/30090:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<ffffffff8197cd91>] __blkdev_get+0x131/0x10d0 fs/block_dev.c:1457
2 locks held by blkid/30095:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<ffffffff8197cd91>] __blkdev_get+0x131/0x10d0 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<ffffffff839ce579>] lo_open+0x19/0xb0 drivers/block/loop.c:1634
1 lock held by blkid/30096:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<ffffffff8197cd91>] __blkdev_get+0x131/0x10d0 fs/block_dev.c:1457

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 1058 Comm: khungtaskd Not tainted 4.14.174-syzkaller #0
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+0x13e/0x194 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5e2/0xb80 kernel/hung_task.c:274
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff864064de

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/03/28 14:37 linux-4.14.y 01364dad1d45 f1ebdfba .config console log report ci2-linux-4-14
2020/02/19 13:11 linux-4.14.y 98db2bf27b9e 47fae6e9 .config console log report ci2-linux-4-14
* Struck through repros no longer work on HEAD.