INFO: task syz-executor:6714 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:27880 pid:6714  tgid:6712  ppid:6263   task_flags:0x480040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5526 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7277
 __schedule_loop kernel/sched/core.c:7354 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7369
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 blk_debugfs_lock block/blk.h:808 [inline]
 blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
 sg_ioctl_common drivers/scsi/sg.c:1115 [inline]
 sg_ioctl+0xa5d/0x21b0 drivers/scsi/sg.c:1157
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2ea7c6e9f9
RSP: 002b:00007f2ea89b2078 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2ea7dabf80 RCX: 00007f2ea7c6e9f9
RDX: 0000000020000040 RSI: 00000000c0481273 RDI: 0000000000000003
RBP: 00007f2ea7ccf4bc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f2ea7dabf80 R15: 00007fff29f9ff38
 </TASK>
INFO: task syz-executor:6716 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:28808 pid:6716  tgid:6712  ppid:6263   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5526 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7277
 __schedule_loop kernel/sched/core.c:7354 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7369
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
 sg_ioctl_common drivers/scsi/sg.c:1123 [inline]
 sg_ioctl+0x457/0x21b0 drivers/scsi/sg.c:1157
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2ea7c6e9f9
RSP: 002b:00007f2ea8991078 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2ea7dac050 RCX: 00007f2ea7c6e9f9
RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000003
RBP: 00007f2ea7ccf4bc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f2ea7dac050 R15: 00007fff29f9ff38
 </TASK>
INFO: task syz-executor.3:6724 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:27880 pid:6724  tgid:6723  ppid:6273   task_flags:0x480040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5526 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7277
 __schedule_loop kernel/sched/core.c:7354 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7369
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 blk_debugfs_lock block/blk.h:808 [inline]
 blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
 sg_ioctl_common drivers/scsi/sg.c:1115 [inline]
 sg_ioctl+0xa5d/0x21b0 drivers/scsi/sg.c:1157
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efc4786e9f9
RSP: 002b:00007efc48553078 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007efc479abf80 RCX: 00007efc4786e9f9
RDX: 0000000020000040 RSI: 00000000c0481273 RDI: 0000000000000003
RBP: 00007efc478cf4bc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007efc479abf80 R15: 00007ffdb9d91338
 </TASK>
INFO: task syz-executor.3:6726 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:28808 pid:6726  tgid:6723  ppid:6273   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5526 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7277
 __schedule_loop kernel/sched/core.c:7354 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7369
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
 sg_ioctl_common drivers/scsi/sg.c:1123 [inline]
 sg_ioctl+0x457/0x21b0 drivers/scsi/sg.c:1157
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efc4786e9f9
RSP: 002b:00007efc48532078 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007efc479ac050 RCX: 00007efc4786e9f9
RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000003
RBP: 00007efc478cf4bc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007efc479ac050 R15: 00007ffdb9d91338
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#0:
 #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5366: 2, on CPU#0:
 #0: ffff88803495e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor.1/6704: 3, last CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
 #1: ffffffff8edbcc40 (relay_channels_mutex){+.+.}-{4:4}, at: relay_close+0x3b/0x630 kernel/relay.c:657
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 #2: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz-executor/6714: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor/6716: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.3/6724: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.3/6726: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.2/6933: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.2/6934: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.5/7001: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.5/7003: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.4/7015: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.4/7017: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.1/7020: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.1/7021: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.3/7025: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.3/7026: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor/7029: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor/7030: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.2/7074: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.2/7075: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.5/7230: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.5/7231: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.1/7237: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.1/7240: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.3/7259: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.3/7261: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor/7269: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor/7271: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.4/7274: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.4/7275: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.2/7313: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.2/7314: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.5/7470: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.5/7471: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.1/7492: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.1/7494: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.3/7503: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.3/7505: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor/7517: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor/7518: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.4/7520: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.4/7521: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by syz-executor.2/7557: 1, on CPU#0:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:808 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
locks held by syz-executor.2/7558: 1, on CPU#1:
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:794 [inline]
 #0: ffff88802643f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
RIP: 0010:delay_tsc+0x62/0xd0 arch/x86/lib/delay.c:77
Code: 20 49 09 c7 4d 29 f7 49 39 df 73 55 bf 01 00 00 00 e8 82 ed b0 f5 65 48 8b 05 fa f8 b0 07 48 85 c0 74 1c f3 90 bf 01 00 00 00 <e8> 19 ec b0 f5 e8 f4 7a 01 00 39 c5 75 0e 0f 01 f9 66 90 eb bb e8
RSP: 0018:ffffc900001578b8 EFLAGS: 00000082
RAX: 8000000000000001 RBX: 0000000000000993 RCX: ffffffff9a9e3501
RDX: 0000000000000001 RSI: ffffffff8c6da060 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff8be3f6c0 R12: 1ffffffff35a746d
R13: 00000000ffffffff R14: 000000a295741b3c R15: 0000000000000513
FS:  0000000000000000(0000) GS:ffff888124dd1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b4839fd5e8 CR3: 0000000064814000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 udelay include/asm-generic/delay.h:62 [inline]
 wait_for_lsr+0x147/0x2f0 drivers/tty/serial/8250/8250_port.c:2019
 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline]
 __serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3345
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
 __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
 serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493
 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
 nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>