INFO: task syz.3.47:6182 blocked for more than 143 seconds.
Not[ 256.273042][ T38] Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.47 state:D stack:25496 pid:6182 tgid:6181 ppid:5795 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x14de/0x5210 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x132/0x200 kernel/locking/rwsem.c:1539
__super_lock fs/super.c:60 [inline]
super_lock+0x2d6/0x3d0 fs/super.c:122
__iterate_supers+0x126/0x290 fs/super.c:926
ksys_sync+0xa0/0x170 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1dd2f4bf79
RSP: 002b:00007f1dd119e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1dd31c5fa0 RCX: 00007f1dd2f4bf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1dd31c5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1dd31c6038 R14: 00007f1dd31c5fa0 R15: 00007ffee0bba218
INFO: task syz.4.60:6263 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.60 state:D stack:25624 pid:6263 tgid:6262 ppid:5806 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x14de/0x5210 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x132/0x200 kernel/locking/rwsem.c:1539
__super_lock fs/super.c:60 [inline]
super_lock+0x2d6/0x3d0 fs/super.c:122
__iterate_supers+0x126/0x290 fs/super.c:926
ksys_sync+0xa0/0x170 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f03cffbbf79
RSP: 002b:00007f03ce20e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f03d0235fa0 RCX: 00007f03cffbbf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f03d0235fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f03d0236038 R14: 00007f03d0235fa0 R15: 00007ffce10b2638
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:2/43:
#0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc90000b57c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90000b57c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
#2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
3 locks held by kworker/u8:8/1407:
#0: ffff888031835938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888031835938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc9000565fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000565fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
#2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4194
5 locks held by kworker/u8:9/1424:
4 locks held by kworker/u8:11/1459:
#0: ffff88801b289138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88801b289138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc9000583fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000583fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
#2: ffffffff8ef3f800 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670
#3: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe5/0xa00 net/core/dev.c:13037
3 locks held by kworker/u9:1/5117:
#0: ffff88806353c138 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88806353c138 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc900110c7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc900110c7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
#2: ffff88806efbcf80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
1 lock held by syslogd/5149:
#0: ffff888034d85b98 (&ei->socket.wq.wait){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#0: ffff888034d85b98 (&ei->socket.wq.wait){+.+.}-{3:3}, at: finish_wait+0xbe/0x1e0 kernel/sched/wait.c:394
3 locks held by klogd/5156:
2 locks held by dhcpcd/5462:
#0: ffff888024674928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe4/0xe80 net/netlink/af_netlink.c:2267
#1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826
2 locks held by getty/5565:
#0: ffff888036c370a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5805:
1 lock held by syz.3.47/6182:
#0: ffff888029b680d0 (&type->s_umount_key#62){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888029b680d0 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.4.60/6263:
#0: ffff888029b680d0 (&type->s_umount_key#62){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888029b680d0 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
7 locks held by syz-executor/6534:
2 locks held by kworker/u8:16/6717:
#0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358
#1: ffffc9000f1cfc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000f1cfc40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358
1 lock held by syz-executor/7555:
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
1 lock held by syz-executor/7883:
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
3 locks held by syz.2.295/8029:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x28/0x80 kernel/kcov.c:217
Code: 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 78 9a 65 10 65 8b 35 99 9a 65 10 81 e6 00 00 ff 00 ba 00 01 00 00 23 91 54 0b 00 00 <89> d7 09 f7 74 11 85 f6 75 39 85 d2 74 35 83 b9 14 16 00 00 00 74
RSP: 0018:ffffc900001679b8 EFLAGS: 00000246
RAX: ffffffff818d62d0 RBX: 0000000000000000 RCX: ffff88801ce95a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00000000ffffee41 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff8b10f2d0 R12: 00000000000036b0
R13: 00000000ffffeb55 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888126595000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555901f8a68 CR3: 00000000577e2000 CR4: 00000000003526f0
Call Trace:
wq_watchdog_touch+0x80/0x160 kernel/workqueue.c:7738
touch_nmi_watchdog include/linux/nmi.h:150 [inline]
wait_for_lsr+0x170/0x2f0 drivers/tty/serial/8250/8250_port.c:1968
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3111 [inline]
console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3217
legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3676
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245