INFO: task syz.6.367:7875 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.367 state:D stack:28248 pid:7875 tgid:7874 ppid:6699 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x125e/0x6990 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xcca/0x1c10 kernel/locking/mutex.c:821
bdev_release+0x15a/0x6e0 block/bdev.c:1173
blkdev_release+0x15/0x20 block/fops.c:694
__fput+0x3fb/0xb50 fs/file_table.c:512
task_work_run+0x150/0x240 kernel/task_work.c:233
get_signal+0x1c5/0x22e0 kernel/signal.c:2885
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x700 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f161bf9fb19
RSP: 002b:00007f161cf15028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f161c225fa0 RCX: 00007f161bf9fb19
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f161c037b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f161c226038 R14: 00007f161c225fa0 R15: 00007ffe0fb016f8
Showing all locks held in the system:
locks held by pr/ttyS0/33: 2, last CPU#0:
#0: ffffffff8ffd7198 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8ffd7198 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:529 [inline]
#0: ffffffff8ffd7198 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x49/0x60 kernel/printk/printk.c:291
#1: ffffffff9cf52fd8 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
#1: ffffffff9cf52fd8 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x64/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/34: 1, last CPU#1:
#0: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by kworker/u8:5/90: 4, on CPU#0:
#0: ffff88801dec8948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc900024ffd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffffffff91f17ec8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:679
#3: ffffffff8fff73b8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0xec/0x790 kernel/rcu/tree.c:4002
locks held by getty/5378: 2, on CPU#0:
#0: ffff88802b5b50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032362e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1540 drivers/tty/n_tty.c:2211
locks held by syz-executor/5609: 1, last CPU#1:
#0: ffff88802c9b5900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:616 [inline]
#0: ffff88802c9b5900 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa40 mm/mmap.c:1299
locks held by kworker/u8:13/6042: 3, last CPU#1:
#0: ffff88813ff74148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc90005487d08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff88807b8fb258 (&devlink->lock_key#3){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x56/0xd20 drivers/net/netdevsim/dev.c:834
locks held by syz.6.367/7875: 1, on CPU#0:
#0: ffff888029ca3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6e0 block/bdev.c:1173
locks held by udevd/7877: 1, on CPU#1:
#0: ffff888029ca3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x426/0xe50 block/bdev.c:990
locks held by syz-executor/8111: 2, last CPU#0:
#0: ffff888029e80478 (sb_writers#6){.+.+}-{0:0}, at: filename_unlinkat+0x1ad/0x770 fs/namei.c:5714
#1: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#1: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
locks held by syz.8.553/9045: 1, last CPU#1:
#0: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: folio_lruvec_lock_irqsave+0x2c/0x5e0 mm/memcontrol.c:1541
locks held by syz.9.561/9079: 3, last CPU#1:
#0: ffff88804fa10478 (sb_writers#6){.+.+}-{0:0}, at: do_coredump.constprop.0+0x9bb/0x25e0 fs/coredump.c:1237
#1: ffff888032f15900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:625 [inline]
#1: ffff888032f15900 (&mm->mmap_lock){++++}-{4:4}, at: dump_user_range+0x15a/0xe90 fs/coredump.c:1583
#2: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#2: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#2: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x9a/0x470 mm/pgtable-generic.c:302
locks held by syz.4.570/9133: 2, last CPU#1:
#0: ffff88802de82478 (sb_writers#6){.+.+}-{0:0}, at: do_coredump.constprop.0+0x9bb/0x25e0 fs/coredump.c:1237
#1: ffff88802bca3440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:625 [inline]
#1: ffff88802bca3440 (&mm->mmap_lock){++++}-{4:4}, at: dump_user_range+0x15a/0xe90 fs/coredump.c:1583
locks held by syz.7.582/9186: 1, on CPU#0:
#0: ffff88807bbcccc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:566 [inline]
#0: ffff88807bbcccc0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f0/0x490 mm/util.c:579
locks held by syz.7.582/9188: 4, last CPU#1:
#0: ffff88807bbcccc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:616 [inline]
#0: ffff88807bbcccc0 (&mm->mmap_lock){++++}-{4:4}, at: __mm_populate+0x229/0x3a0 mm/gup.c:1950
#1: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: do_fault_around mm/memory.c:6069 [inline]
#1: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: do_read_fault mm/memory.c:6103 [inline]
#1: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: do_fault+0x9a8/0x1890 mm/memory.c:6246
#2: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#2: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#2: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: filemap_map_pages+0x1d7/0x1f10 mm/filemap.c:3939
#3: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8ffeafe0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x9a/0x470 mm/pgtable-generic.c:302
locks held by syz.4.583/9189: 1, on CPU#0:
#0: ffff88807bbc8f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:566 [inline]
#0: ffff88807bbc8f80 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f0/0x490 mm/util.c:579
locks held by syz.4.583/9190: 1, last CPU#1:
#0: ffff88807bbc8f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:616 [inline]
#0: ffff88807bbc8f80 (&mm->mmap_lock){++++}-{4:4}, at: __mm_populate+0x229/0x3a0 mm/gup.c:1950
locks held by dhcpcd-run-hook/9191: 1, last CPU#1:
#0: ffff88813ff63440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:566 [inline]
#0: ffff88813ff63440 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f0/0x490 mm/util.c:579
locks held by syz-executor/9192: 2, last CPU#1:
#0: ffff8880443273d8 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1041 [inline]
#0: ffff8880443273d8 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: lookup_slow+0x41/0x80 fs/namei.c:1941
#1: ffff888059230c60 (DCACHE_PAR_LOOKUP#4){+.+.}-{0:0}, at: __d_alloc_parallel+0xd90/0x15e0 fs/dcache.c:2974
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:377 [inline]
watchdog+0xd0f/0x10c0 kernel/hung_task.c:598
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 33 Comm: pr/ttyS0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:426
Code: 34 4b fc 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 c8 9d c5 fc eb a2 e8 51 9e
RSP: 0018:ffffc90000a97950 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff85c33810 RDI: ffffffff9cf53000
RBP: ffffffff9cf52fc0 R08: 000000000000001f R09: 0000000000000000
R10: 0000000000000003 R11: 205d343354202020 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff39ea655 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888122475000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c41d880 CR3: 0000000061ec1000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:134 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:156 [inline]
wait_for_lsr+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:2036
serial8250_fifo_wait_for_lsr_thre+0x5f/0xd0 drivers/tty/serial/8250/8250_port.c:3294
__serial8250_console_fifo_write+0xa5/0x290 drivers/tty/serial/8250/8250_port.c:3369
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3402 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3456 [inline]
serial8250_console_write+0x1108/0x14f0 drivers/tty/serial/8250/8250_port.c:3520
nbcon_emit_next_record+0x8f7/0xa70 kernel/printk/nbcon.c:1070
nbcon_emit_one+0x1a8/0x2b0 kernel/printk/nbcon.c:1157
nbcon_kthread_func+0x5ef/0x7f0 kernel/printk/nbcon.c:1271
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245