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INFO: task hung in lo_open

Status: public: reported C repro on 2019/04/11 00:00
Reported-by: syzbot+40a29aedacb650561903@syzkaller.appspotmail.com
First crash: 2072d, last: 1612d
▶ ▼ Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in lo_open (2) block 10 1996d 2224d 11/26 fixed on 2019/01/15 20:25
android-44 INFO: task hung in lo_open syz 593 1612d 1846d 0/2 public: reported syz repro on 2019/04/14 00:02
android-49 INFO: task hung in lo_open C 2683 1612d 1846d 0/3 public: reported C repro on 2019/04/14 09:28
linux-4.14 INFO: task hung in lo_open C 1230 450d 1848d 0/1 upstream: reported C repro on 2019/04/11 12:30
upstream INFO: task hung in lo_open block 3 2312d 2329d 0/26 closed as invalid on 2018/02/14 14:52

Sample crash report:
INFO: task syz-executor193:1935 blocked for more than 140 seconds.
      Not tainted 4.14.146+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor193 D28352  1935   1930 0x00000000
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 lo_open+0x19/0xb0 drivers/block/loop.c:1623
 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472
 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x44e/0xe20 fs/open.c:789
 vfs_open+0x105/0x230 fs/open.c:903
 do_last fs/namei.c:3539 [inline]
 path_openat+0xb6c/0x2be0 fs/namei.c:3681
 do_filp_open+0x1a1/0x280 fs/namei.c:3715
 do_sys_open+0x2ca/0x590 fs/open.c:1096
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4012a0
RSP: 002b:00007ffeaca73ee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00000000000007d0 RCX: 00000000004012a0
RDX: 00007ffeaca73f0a RSI: 0000000000000002 RDI: 00007ffeaca73f00
RBP: 00000000000d759c R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000246 R12: 00000000004022c0
R13: 0000000000402350 R14: 0000000000000000 R15: 0000000000000000
INFO: task syz-executor193:2006 blocked for more than 140 seconds.
      Not tainted 4.14.146+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor193 D28352  2006   1934 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 lo_release+0x1b/0x1a0 drivers/block/loop.c:1666
 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791
 blkdev_close+0x86/0xb0 fs/block_dev.c:1863
 __fput+0x25e/0x710 fs/file_table.c:210
 task_work_run+0x125/0x1a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x13b/0x160 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+0x3a3/0x520 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x401240
RSP: 002b:00007ffeaca73ca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000401240
RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000005
RBP: 0000000000000004 R08: 0000000000000000 R09: 000000000000000c
R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000000
INFO: task syz-executor193:2011 blocked for more than 140 seconds.
      Not tainted 4.14.146+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor193 D28336  2011   1936 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192
 loop_reread_partitions+0x7f/0x90 drivers/block/loop.c:614
 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1183
 loop_set_status64+0xa5/0x100 drivers/block/loop.c:1301
 lo_ioctl+0xd1/0x1a30 drivers/block/loop.c:1431
 __blkdev_driver_ioctl block/ioctl.c:297 [inline]
 blkdev_ioctl+0x8d0/0x1870 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+0xabe/0x1040 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4414b7
RSP: 002b:00007ffeaca73ca8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004414b7
RDX: 00007ffeaca73d40 RSI: 0000000000004c04 RDI: 0000000000000005
RBP: 0000000000000004 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000202 R12: 00000000004022c0
R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000000
INFO: task syz-executor193:2018 blocked for more than 140 seconds.
      Not tainted 4.14.146+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor193 D28176  2018   1931 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192
 loop_reread_partitions+0x7f/0x90 drivers/block/loop.c:614
 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1183
 loop_set_status64+0xa5/0x100 drivers/block/loop.c:1301
 lo_ioctl+0xd1/0x1a30 drivers/block/loop.c:1431
 __blkdev_driver_ioctl block/ioctl.c:297 [inline]
 blkdev_ioctl+0x8d0/0x1870 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+0xabe/0x1040 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4414b7
RSP: 002b:00007ffeaca73ca8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004414b7
RDX: 00007ffeaca73d40 RSI: 0000000000004c04 RDI: 0000000000000005
RBP: 0000000000000004 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000202 R12: 00000000004022c0
R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000000
INFO: task blkid:2019 blocked for more than 140 seconds.
      Not tainted 4.14.146+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D28448  2019    305 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 blkdev_put+0x27/0x4c0 fs/block_dev.c:1814
 blkdev_close+0x86/0xb0 fs/block_dev.c:1863
 __fput+0x25e/0x710 fs/file_table.c:210
 task_work_run+0x125/0x1a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x13b/0x160 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+0x3a3/0x520 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f2d7e0982b0
RSP: 002b:00007ffd178e47d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f2d7e0982b0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000015da030
R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000005
INFO: task blkid:2021 blocked for more than 140 seconds.
      Not tainted 4.14.146+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D28336  2021   1940 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 lo_open+0x19/0xb0 drivers/block/loop.c:1623
 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472
 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x44e/0xe20 fs/open.c:789
 vfs_open+0x105/0x230 fs/open.c:903
 do_last fs/namei.c:3539 [inline]
 path_openat+0xb6c/0x2be0 fs/namei.c:3681
 do_filp_open+0x1a1/0x280 fs/namei.c:3715
 do_sys_open+0x2ca/0x590 fs/open.c:1096
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7fccae997120
RSP: 002b:00007ffed6e47de8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fccae997120
RDX: 00007ffed6e49f41 RSI: 0000000000000000 RDI: 00007ffed6e49f41
RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001784030
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005
INFO: task syz-executor193:2024 blocked for more than 140 seconds.
      Not tainted 4.14.146+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor193 D28240  2024   1933 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1996
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4415a9
RSP: 002b:00007ffeaca73ee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004415a9
RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003
RBP: 00000000000d74f9 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000004 R11: 0000000000000246 R12: 00000000004022c0
R13: 0000000000402350 R14: 0000000000000000 R15: 0000000000000000
INFO: task blkid:2026 blocked for more than 140 seconds.
      Not tainted 4.14.146+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D28448  2026   1945 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 lo_open+0x19/0xb0 drivers/block/loop.c:1623
 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537
 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x44e/0xe20 fs/open.c:789
 vfs_open+0x105/0x230 fs/open.c:903
 do_last fs/namei.c:3539 [inline]
 path_openat+0xb6c/0x2be0 fs/namei.c:3681
 do_filp_open+0x1a1/0x280 fs/namei.c:3715
 do_sys_open+0x2ca/0x590 fs/open.c:1096
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f96bcbdd120
RSP: 002b:00007ffdfe2b1df8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f96bcbdd120
RDX: 00007ffdfe2b3f41 RSI: 0000000000000000 RDI: 00007ffdfe2b3f41
RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001e6e030
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005
INFO: task blkid:2027 blocked for more than 140 seconds.
      Not tainted 4.14.146+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D27808  2027    304 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 lo_open+0x19/0xb0 drivers/block/loop.c:1623
 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537
 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x44e/0xe20 fs/open.c:789
 vfs_open+0x105/0x230 fs/open.c:903
 do_last fs/namei.c:3539 [inline]
 path_openat+0xb6c/0x2be0 fs/namei.c:3681
 do_filp_open+0x1a1/0x280 fs/namei.c:3715
 do_sys_open+0x2ca/0x590 fs/open.c:1096
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f964549c120
RSP: 002b:00007fffec5697b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f964549c120
RDX: 00007fffec56bf44 RSI: 0000000000000000 RDI: 00007fffec56bf44
RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001787030
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005
INFO: task blkid:2028 blocked for more than 140 seconds.
      Not tainted 4.14.146+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D28464  2028   1944 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893
 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612
 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770
 do_dentry_open+0x44e/0xe20 fs/open.c:789
 vfs_open+0x105/0x230 fs/open.c:903
 do_last fs/namei.c:3539 [inline]
 path_openat+0xb6c/0x2be0 fs/namei.c:3681
 do_filp_open+0x1a1/0x280 fs/namei.c:3715
 do_sys_open+0x2ca/0x590 fs/open.c:1096
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f5c79113120
RSP: 002b:00007ffd249acb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c79113120
RDX: 00007ffd249adf41 RSI: 0000000000000000 RDI: 00007ffd249adf41
RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000139d030
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<        (ptrval)>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
1 lock held by rsyslogd/1633:
 #0:  (&f->f_pos_lock){+.+.}, at: [<        (ptrval)>] __fdget_pos+0xb5/0xd0 fs/file.c:769
2 locks held by getty/1760:
 #0:  (&tty->ldisc_sem){++++}, at: [<        (ptrval)>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<        (ptrval)>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
2 locks held by syz-executor193/1935:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<        (ptrval)>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<        (ptrval)>] lo_open+0x19/0xb0 drivers/block/loop.c:1623
2 locks held by syz-executor193/2006:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<        (ptrval)>] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778
 #1:  (loop_index_mutex){+.+.}, at: [<        (ptrval)>] lo_release+0x1b/0x1a0 drivers/block/loop.c:1666
2 locks held by syz-executor193/2011:
 #0:  (&lo->lo_ctl_mutex/1){+.+.}, at: [<        (ptrval)>] lo_ioctl+0x86/0x1a30 drivers/block/loop.c:1404
 #1:  (&bdev->bd_mutex){+.+.}, at: [<        (ptrval)>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192
2 locks held by syz-executor193/2018:
 #0:  (&lo->lo_ctl_mutex/1){+.+.}, at: [<        (ptrval)>] lo_ioctl+0x86/0x1a30 drivers/block/loop.c:1404
 #1:  (&bdev->bd_mutex){+.+.}, at: [<        (ptrval)>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192
1 lock held by blkid/2019:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<        (ptrval)>] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814
2 locks held by blkid/2021:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<        (ptrval)>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<        (ptrval)>] lo_open+0x19/0xb0 drivers/block/loop.c:1623
2 locks held by syz-executor193/2024:
 #0:  (loop_index_mutex){+.+.}, at: [<        (ptrval)>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1982
 #1:  (&lo->lo_ctl_mutex#2){+.+.}, at: [<        (ptrval)>] loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1996
2 locks held by blkid/2026:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<        (ptrval)>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<        (ptrval)>] lo_open+0x19/0xb0 drivers/block/loop.c:1623
2 locks held by blkid/2027:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<        (ptrval)>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<        (ptrval)>] lo_open+0x19/0xb0 drivers/block/loop.c:1623
1 lock held by blkid/2028:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<        (ptrval)>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
1 lock held by syz-executor193/2029:
 #0:  (loop_index_mutex){+.+.}, at: [<        (ptrval)>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1982
2 locks held by blkid/2030:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<        (ptrval)>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457
 #1:  (loop_index_mutex){+.+.}, at: [<        (ptrval)>] lo_open+0x19/0xb0 drivers/block/loop.c:1623

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

NMI backtrace for cpu 0
CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.146+ #0
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xca/0x134 lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x119/0x147 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+0x629/0xbe0 kernel/hung_task.c:274
 kthread+0x31f/0x430 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff94c9c503

Crashes (6143):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/09/28 03:27 android-4.14 d649ef04c3ed d8074e0b .config console log report syz C ci-android-414-kasan-gce-root
2019/09/18 23:33 android-4.14 6bb0e9159cb6 c2dcd700 .config console log report syz C ci-android-414-kasan-gce-root
2018/09/02 13:03 android-4.14 47350a9f13c6 a4718693 .config console log report syz C ci-android-414-kasan-gce-root
2019/04/19 22:08 android-4.14 cec361536f1e b0e8efcb .config console log report syz ci-android-414-kasan-gce-root
2019/03/06 07:00 android-4.14 9ba09a217160 16559f86 .config console log report syz ci-android-414-kasan-gce-root
2019/12/04 02:25 android-4.14 e6b1fb0e83b2 ae13a849 .config console log report ci-android-414-kasan-gce-root
2019/12/03 23:50 android-4.14 e6b1fb0e83b2 ae13a849 .config console log report ci-android-414-kasan-gce-root
2019/12/03 16:32 android-4.14 e6b1fb0e83b2 ab342da3 .config console log report ci-android-414-kasan-gce-root
2019/12/02 19:26 android-4.14 13855a652bd5 f879db37 .config console log report ci-android-414-kasan-gce-root
2019/12/02 14:46 android-4.14 13855a652bd5 f879db37 .config console log report ci-android-414-kasan-gce-root
2019/12/02 11:48 android-4.14 13855a652bd5 f879db37 .config console log report ci-android-414-kasan-gce-root
2019/12/02 06:37 android-4.14 13855a652bd5 f879db37 .config console log report ci-android-414-kasan-gce-root
2019/12/01 06:54 android-4.14 714ada7cabc7 a76bf83f .config console log report ci-android-414-kasan-gce-root
2019/11/30 20:44 android-4.14 714ada7cabc7 3a75be00 .config console log report ci-android-414-kasan-gce-root
2019/11/30 18:56 android-4.14 714ada7cabc7 3a75be00 .config console log report ci-android-414-kasan-gce-root
2019/11/30 15:55 android-4.14 714ada7cabc7 3a75be00 .config console log report ci-android-414-kasan-gce-root
2019/11/30 14:54 android-4.14 714ada7cabc7 3a75be00 .config console log report ci-android-414-kasan-gce-root
2019/11/30 13:32 android-4.14 714ada7cabc7 3a75be00 .config console log report ci-android-414-kasan-gce-root
2019/11/30 03:19 android-4.14 714ada7cabc7 3a75be00 .config console log report ci-android-414-kasan-gce-root
2019/11/29 09:13 android-4.14 714ada7cabc7 76357d6f .config console log report ci-android-414-kasan-gce-root
2019/11/28 21:37 android-4.14 714ada7cabc7 46869e3e .config console log report ci-android-414-kasan-gce-root
2019/11/28 20:25 android-4.14 714ada7cabc7 46869e3e .config console log report ci-android-414-kasan-gce-root
2019/11/28 09:44 android-4.14 714ada7cabc7 0d63f89c .config console log report ci-android-414-kasan-gce-root
2019/11/28 07:53 android-4.14 714ada7cabc7 0d63f89c .config console log report ci-android-414-kasan-gce-root
2019/11/27 07:15 android-4.14 f9b4ab5c8e99 1048481f .config console log report ci-android-414-kasan-gce-root
2019/11/27 04:39 android-4.14 f9b4ab5c8e99 1048481f .config console log report ci-android-414-kasan-gce-root
2019/11/27 01:06 android-4.14 f9b4ab5c8e99 1048481f .config console log report ci-android-414-kasan-gce-root
2019/11/26 14:37 android-4.14 f9b4ab5c8e99 f746151a .config console log report ci-android-414-kasan-gce-root
2019/11/25 15:22 android-4.14 f9b4ab5c8e99 371caf77 .config console log report ci-android-414-kasan-gce-root
2019/11/25 10:28 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/25 07:30 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/25 04:38 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/25 02:12 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/25 01:01 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/24 23:54 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/24 22:23 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/24 16:37 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/24 15:15 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/24 06:05 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/23 20:58 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/23 19:57 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/23 18:42 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/23 17:16 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/23 11:24 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/23 09:49 android-4.14 437a2a739c5f 598ca6c8 .config console log report ci-android-414-kasan-gce-root
2019/11/22 08:09 android-4.14 7bc77fd33905 8098ea0f .config console log report ci-android-414-kasan-gce-root
2019/11/22 06:51 android-4.14 7bc77fd33905 8098ea0f .config console log report ci-android-414-kasan-gce-root
2019/11/22 03:05 android-4.14 7bc77fd33905 8098ea0f .config console log report ci-android-414-kasan-gce-root
2018/08/31 02:20 android-4.14 47350a9f13c6 938220fd .config console log report ci-android-414-kasan-gce-root
* Struck through repros no longer work on HEAD.