syzbot

INFO: task syz-executor274:8097 blocked for more than 143 seconds.
      Not tainted 5.1.0-rc6+ #89
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor274 D28008  8097   8041 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2877 [inline]
 __schedule+0x813/0x1cc0 kernel/sched/core.c:3518
 schedule+0x92/0x180 kernel/sched/core.c:3562
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:285 [inline]
 rwsem_down_read_failed+0x213/0x420 kernel/locking/rwsem-xadd.c:302
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 down_read+0x49/0x90 kernel/locking/rwsem.c:26
 __get_super.part.0+0x203/0x2e0 fs/super.c:788
 __get_super include/linux/spinlock.h:329 [inline]
 get_super+0x2e/0x50 fs/super.c:817
 fsync_bdev+0x19/0xd0 fs/block_dev.c:525
 invalidate_partition+0x36/0x60 block/genhd.c:1581
 drop_partitions block/partition-generic.c:443 [inline]
 rescan_partitions+0xef/0xa20 block/partition-generic.c:516
 __blkdev_reread_part+0x1a2/0x230 block/ioctl.c:173
 blkdev_reread_part+0x27/0x40 block/ioctl.c:193
 loop_reread_partitions+0x1c/0x40 drivers/block/loop.c:633
 loop_set_status+0xe57/0x1380 drivers/block/loop.c:1296
 loop_set_status64+0xc2/0x120 drivers/block/loop.c:1416
 lo_ioctl+0x8fc/0x2150 drivers/block/loop.c:1559
 __blkdev_driver_ioctl block/ioctl.c:303 [inline]
 blkdev_ioctl+0x6f2/0x1d10 block/ioctl.c:605
 block_ioctl+0xee/0x130 fs/block_dev.c:1933
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441937
Code: 48 83 c4 08 48 89 d8 5b 5d c3 66 0f 1f 84 00 00 00 00 00 48 89 e8 48 f7 d8 48 39 c3 0f 92 c0 eb 92 66 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 8d 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcabed4e08 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441937
RDX: 00007ffcabed4ea0 RSI: 0000000000004c04 RDI: 0000000000000004
RBP: 0000000000000003 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000001
R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000
INFO: task blkid:8099 blocked for more than 143 seconds.
      Not tainted 5.1.0-rc6+ #89
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D27504  8099   8021 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2877 [inline]
 __schedule+0x813/0x1cc0 kernel/sched/core.c:3518
 schedule+0x92/0x180 kernel/sched/core.c:3562
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3620
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 blkdev_put+0x34/0x560 fs/block_dev.c:1866
 blkdev_close+0x8b/0xb0 fs/block_dev.c:1915
 __fput+0x2e5/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f1ae9c432b0
Code: Bad RIP value.
RSP: 002b:00007ffc29ff6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f1ae9c432b0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000028 R09: 0000000001680000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000b9d030
R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000005

Showing all locks held in the system:
1 lock held by khungtaskd/1041:
 #0: 0000000027887009 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5057
1 lock held by rs:main Q:Reg/7921:
 #0: 00000000e00580d7 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline]
 #0: 00000000e00580d7 (&rq->lock){-.-.}, at: __schedule+0x1f8/0x1cc0 kernel/sched/core.c:3456
1 lock held by rsyslogd/7923:
 #0: 00000000488dcec4 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801
2 locks held by getty/8014:
 #0: 000000001b56f3c3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000da9faa8c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8015:
 #0: 00000000e00c81bb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000008d689a2e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8016:
 #0: 00000000177f6359 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 0000000096437898 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8017:
 #0: 000000002db00e12 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 0000000071f2d88e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8018:
 #0: 00000000a41b6290 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000c340e26f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8019:
 #0: 00000000bca104ce (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000007e045212 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8020:
 #0: 0000000070fdafae (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000b4e26fa9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
1 lock held by syz-executor274/8083:
2 locks held by syz-executor274/8097:
 #0: 000000007a5ed526 (&bdev->bd_mutex){+.+.}, at: blkdev_reread_part+0x1f/0x40 block/ioctl.c:192
 #1: 0000000067606e21 (&type->s_umount_key#39){.+.+}, at: __get_super.part.0+0x203/0x2e0 fs/super.c:788
1 lock held by blkid/8099:
 #0: 000000007a5ed526 (&bdev->bd_mutex){+.+.}, at: blkdev_put+0x34/0x560 fs/block_dev.c:1866
2 locks held by syz-executor274/11705:
 #0: 000000002b6bbb34 (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xbb/0x810 fs/block_dev.c:1833
 #1: 00000000bde6230e (loop_ctl_mutex){+.+.}, at: lo_release+0x1f/0x200 drivers/block/loop.c:1755
2 locks held by syz-executor274/11709:
 #0: 00000000a45cb906 (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xbb/0x810 fs/block_dev.c:1833
 #1: 00000000bde6230e (loop_ctl_mutex){+.+.}, at: lo_release+0x1f/0x200 drivers/block/loop.c:1755
2 locks held by syz-executor274/11716:
 #0: 00000000a19e2025 (&type->s_umount_key#38/1){+.+.}, at: alloc_super+0x158/0x890 fs/super.c:228
 #1: 00000000bde6230e (loop_ctl_mutex){+.+.}, at: lo_simple_ioctl drivers/block/loop.c:1514 [inline]
 #1: 00000000bde6230e (loop_ctl_mutex){+.+.}, at: lo_ioctl+0x266/0x2150 drivers/block/loop.c:1572
2 locks held by syz-executor274/11717:
 #0: 00000000e185c083 (&type->s_umount_key#38/1){+.+.}, at: alloc_super+0x158/0x890 fs/super.c:228
 #1: 00000000bde6230e (loop_ctl_mutex){+.+.}, at: lo_simple_ioctl drivers/block/loop.c:1514 [inline]
 #1: 00000000bde6230e (loop_ctl_mutex){+.+.}, at: lo_ioctl+0x266/0x2150 drivers/block/loop.c:1572
2 locks held by blkid/11718:
 #0: 000000003d9e77b2 (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xbb/0x810 fs/block_dev.c:1833
 #1: 00000000bde6230e (loop_ctl_mutex){+.+.}, at: __loop_clr_fd+0x88/0xd60 drivers/block/loop.c:1046
2 locks held by blkid/11720:
 #0: 000000000c0297bc (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xbb/0x810 fs/block_dev.c:1833
 #1: 00000000bde6230e (loop_ctl_mutex){+.+.}, at: lo_release+0x1f/0x200 drivers/block/loop.c:1755

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

NMI backtrace for cpu 0
CPU: 0 PID: 1041 Comm: khungtaskd Not tainted 5.1.0-rc6+ #89
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+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline]
 watchdog+0x9b7/0xec0 kernel/hung_task.c:288
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1: