INFO: task syz-executor.2:17360 blocked for more than 140 seconds.
Not tainted 4.9.194+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2 D25544 17360 17359 0x00000000
0000000000000083 ffff8801a00a97c0 0000000000000000 ffff8801db721000
ffff8801da6817c0 ffff8801db721018 ffff8801ca8f7688 ffffffff8281af8e
0000000041b58ab3 ffffffff82e2c730 00ffffff81204ef0 ffff8801db7218f0
Call Trace:
[<0000000022cd6873>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
[<000000004d16c6cb>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579
[<00000000e2b5f708>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
[<00000000e2b5f708>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621
[<000000007034c21a>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621
[<00000000735b0fec>] __blkdev_get+0x268/0xeb0 fs/block_dev.c:1287
[<00000000123fc317>] blkdev_get+0x2e8/0x920 fs/block_dev.c:1424
[<00000000c1382a55>] blkdev_open+0x1aa/0x250 fs/block_dev.c:1579
[<000000001d3e201f>] do_dentry_open+0x422/0xd20 fs/open.c:791
[<00000000b01ab27e>] vfs_open+0x105/0x230 fs/open.c:904
[<00000000802eb064>] do_last fs/namei.c:3541 [inline]
[<00000000802eb064>] path_openat+0xbf5/0x2f60 fs/namei.c:3665
[<00000000c48cb48a>] do_filp_open+0x1a1/0x280 fs/namei.c:3699
[<000000009f3f01e5>] do_sys_open+0x2f0/0x610 fs/open.c:1097
[<00000000c6d4cba2>] SYSC_open fs/open.c:1115 [inline]
[<00000000c6d4cba2>] SyS_open+0x2d/0x40 fs/open.c:1110
[<000000009c5ee147>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
[<000000002ba8469c>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Showing all locks held in the system:
2 locks held by khungtaskd/24:
#0: (rcu_read_lock){......}, at: [<000000008562cf31>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline]
#0: (rcu_read_lock){......}, at: [<000000008562cf31>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263
#1: (tasklist_lock){.+.+..}, at: [<000000009895670d>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336
2 locks held by getty/2026:
#0: (&tty->ldisc_sem){++++++}, at: [<000000004b6a06c5>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
#1: (&ldata->atomic_read_lock){+.+.+.}, at: [<000000005d1a5fe8>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
2 locks held by syz-executor.2/17360:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007072c254>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (loop_index_mutex){+.+.+.}, at: [<000000007034c21a>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621
2 locks held by syz-executor.4/19169:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007072c254>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (loop_index_mutex){+.+.+.}, at: [<000000007034c21a>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621
2 locks held by syz-executor.3/19176:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007072c254>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (loop_index_mutex){+.+.+.}, at: [<000000007034c21a>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621
2 locks held by syz-executor.1/21426:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007072c254>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (loop_index_mutex){+.+.+.}, at: [<000000007034c21a>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621
2 locks held by syz-executor.5/21474:
#0: (loop_index_mutex){+.+.+.}, at: [<00000000e75024eb>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973
#1: (&lo->lo_ctl_mutex#2){+.+.+.}, at: [<000000009b05ef34>] loop_control_ioctl+0x17f/0x320 drivers/block/loop.c:1987
1 lock held by syz-executor.5/21481:
#0: (loop_index_mutex){+.+.+.}, at: [<00000000e75024eb>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973
2 locks held by syz-executor.0/21471:
#0: (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<000000007ff94cf3>] lo_ioctl+0x8e/0x1b10 drivers/block/loop.c:1404
#1: (&bdev->bd_mutex){+.+.+.}, at: [<00000000cd3b3c1f>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189
1 lock held by syz-executor.0/21484:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007072c254>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
2 locks held by blkid/21475:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007072c254>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (loop_index_mutex){+.+.+.}, at: [<000000007034c21a>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.194+ #0
ffff8801d98d7cc8 ffffffff81b67001 0000000000000001 0000000000000000
0000000000000001 ffffffff81099d01 dffffc0000000000 ffff8801d98d7d00
ffffffff81b7229c 0000000000000001 0000000000000000 0000000000000001
Call Trace:
[<00000000d485519c>] __dump_stack lib/dump_stack.c:15 [inline]
[<00000000d485519c>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
[<00000000d49f23ce>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99
[<000000008d7371ca>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60
[<0000000045ffc374>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
[<000000006f139a9c>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
[<000000006f139a9c>] check_hung_task kernel/hung_task.c:126 [inline]
[<000000006f139a9c>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline]
[<000000006f139a9c>] watchdog+0x670/0xaf0 kernel/hung_task.c:263
[<00000000ad650376>] kthread+0x278/0x310 kernel/kthread.c:211
[<000000009b163e59>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff8282a0e1