INFO: task syz.1.192:7535 blocked for more than 143 seconds.
Not tainted 6.15.0-rc6-syzkaller-00047-ge9565e23cd89 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.192 state:D stack:28952 pid:7535 tgid:7530 ppid:5817 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
percpu_rwsem_wait+0x2ab/0x300 kernel/locking/percpu-rwsem.c:162
__percpu_down_read+0xe3/0x120 kernel/locking/percpu-rwsem.c:177
percpu_down_read include/linux/percpu-rwsem.h:66 [inline]
__sb_start_write include/linux/fs.h:1783 [inline]
sb_start_write+0x185/0x1c0 include/linux/fs.h:1919
mnt_want_write+0x41/0x90 fs/namespace.c:556
filename_create+0x13a/0x470 fs/namei.c:4125
do_symlinkat+0xbc/0x3f0 fs/namei.c:4742
__do_sys_symlinkat fs/namei.c:4765 [inline]
__se_sys_symlinkat fs/namei.c:4762 [inline]
__x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4762
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff8c278e969
RSP: 002b:00007ff8c01b2038 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007ff8c29b6240 RCX: 00007ff8c278e969
RDX: 0000200000000000 RSI: ffffffffffffff9c RDI: 0000200000001040
RBP: 00007ff8c2810ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007ff8c29b6240 R15: 00007ffd3111e458
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
4 locks held by kworker/u8:4/63:
2 locks held by kworker/u8:5/991:
3 locks held by kworker/u8:6/1101:
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90003c77c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90003c77c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2e5008 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by getty/5585:
#0: ffff8880303b70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900033532f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by kworker/0:5/5873:
#0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
#1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
1 lock held by syz.1.192/7535:
#0: ffff888079aa0420 (sb_writers#33){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
1 lock held by syz-executor/8174:
#0: ffff88804d5fa0e0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88804d5fa0e0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88804d5fa0e0 (&type->s_umount_key#69){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
1 lock held by syz-executor/9589:
#0: ffffffff8f2e5008 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1d90 drivers/net/tun.c:3038
1 lock held by syz-executor/9590:
#0: ffffffff8f2e5008 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1d90 drivers/net/tun.c:3038
1 lock held by dhcpcd-run-hook/9717:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00047-ge9565e23cd89 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9692 Comm: syz.8.408 Not tainted 6.15.0-rc6-syzkaller-00047-ge9565e23cd89 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:416
Code: 1d 89 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 fc ec e8 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc9000489f270 EFLAGS: 00000002
RAX: 0000000000000036 RBX: 0000000000000036 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 00000000000003f8 R08: ffff8880246e8237 R09: 1ffff110048dd046
R10: dffffc0000000000 R11: ffffffff8536d2f0 R12: dffffc0000000000
R13: ffffffff99817c4a R14: ffffffff99b1c9c0 R15: 0000000000000000
FS: 00007febba40a6c0(0000) GS:ffff8881261fb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f008d74a7e8 CR3: 000000004a0fa000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_port_out include/linux/serial_core.h:796 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3306 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x140d/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
bch2_print_maybe_redirect fs/bcachefs/super.c:110 [inline]
__bch2_print+0x176/0x220 fs/bcachefs/super.c:129
bch2_fs_start+0x97d/0xae0 fs/bcachefs/super.c:1126
bch2_fs_get_tree+0xad7/0x13b0 fs/bcachefs/fs.c:2505
vfs_get_tree+0x92/0x2b0 fs/super.c:1759
do_new_mount+0x24a/0xa40 fs/namespace.c:3881
do_mount fs/namespace.c:4221 [inline]
__do_sys_mount fs/namespace.c:4432 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4409
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7febb959010a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007febba409e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007febba409ef0 RCX: 00007febb959010a
RDX: 0000200000000140 RSI: 0000200000000440 RDI: 00007febba409eb0
RBP: 0000200000000140 R08: 00007febba409ef0 R09: 0000000000208410
R10: 0000000000208410 R11: 0000000000000246 R12: 0000200000000440
R13: 00007febba409eb0 R14: 0000000000005a76 R15: 0000200000000080