INFO: task syz.2.529:8488 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.529 state:D stack:27608 pid:8488 tgid:8476 ppid:5832 task_flags:0x400640 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269
coredump_wait fs/coredump.c:534 [inline]
vfs_coredump+0x848/0x55e0 fs/coredump.c:1196
get_signal+0x22e1/0x26d0 kernel/signal.c:3019
arch_do_signal_or_restart+0x8f/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc9f618f7c9
RSP: 002b:00007fc9f6fed0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fc9f63e6278 RCX: 00007fc9f618f7c9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fc9f63e627c
RBP: 00007fc9f63e6270 R08: 00007fc9f7051000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc9f63e6308 R14: 00007ffe5d05aeb0 R15: 00007ffe5d05af98
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:10/1162:
#0: ffff88801badf148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000428fc90 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff9012e9d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x830 net/core/net_namespace.c:670
#3: ffffffff8e3d4b40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3816
2 locks held by syslogd/5184:
#0: ffff8880b843add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
#0: ffff8880b843add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
#1: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
#1: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: __schedule+0x19b1/0x6150 kernel/sched/core.c:6857
2 locks held by getty/5597:
#0: ffff88814d0db0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211
1 lock held by syz.2.529/8477:
2 locks held by syz.3.886/10233:
3 locks held by syz.0.888/10239:
#0: ffffffff9012e9d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577
#1: ffffffff901451a8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#1: ffffffff901451a8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7e9/0xab0 net/core/net_namespace.c:248
#2: ffffffff8e3d4c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz.1.889/10247:
#0: ffffffff9012e9d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577
#1: ffffffff901451a8 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x1b/0x70 net/ipv4/nexthop.c:3971
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x133/0x180 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xe66/0x1180 kernel/hung_task.c:515
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5819 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_note_context_switch+0x111/0x1de0 kernel/rcu/tree_plugin.h:333
Code: 38 d0 7c 08 84 d2 0f 85 bb 10 00 00 8b 85 84 04 00 00 85 c0 7e 0c 48 8d 3d 4c 30 e8 0e 67 48 0f b9 3a 65 48 8b 2d 07 05 0e 12 <48> 8d bd 84 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc90003e0fa50 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880b843bd80 RCX: ffffffff81a3b47f
RDX: 0000000000000000 RSI: ffffffff8bf2b500 RDI: ffff88807cc9e004
RBP: ffff88807cc9db80 R08: 0000000000000000 R09: fffffbfff2111d3a
R10: ffffffff9088e9d7 R11: ffff88807cc9e6b0 R12: 0000000000000000
R13: ffff88807cc9db80 R14: ffffffff90891a54 R15: ffff8880b843adc0
FS: 0000555561cd2500(0000) GS:ffff8881248fc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1a9d2b0990 CR3: 00000000743f0000 CR4: 00000000003526f0
Call Trace:
__schedule+0x2dc/0x6150 kernel/sched/core.c:6748
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
do_nanosleep+0x219/0x580 kernel/time/hrtimer.c:2116
hrtimer_nanosleep+0x155/0x380 kernel/time/hrtimer.c:2163
common_nsleep+0xa1/0xd0 kernel/time/posix-timers.c:1352
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline]
__se_sys_clock_nanosleep kernel/time/posix-timers.c:1375 [inline]
__x64_sys_clock_nanosleep+0x34d/0x4a0 kernel/time/posix-timers.c:1375
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb15c1c2043
Code: 1f 84 00 00 00 00 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d 1e 95 1f 00 00 74 14 b8 e6 00 00 00 0f 05 d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10
RSP: 002b:00007ffc556eac88 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb15c1c2043
RDX: 00007ffc556eaca0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00007ffc556eacd0 R09: 00007fb15d114000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc556eb0f0
R13: 0000000000000004 R14: 00007ffc556eacdc R15: 00007ffc556ead70