INFO: task kworker/u10:3:9538 blocked for more than 143 seconds.
Tainted: G U syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u10:3 state:D stack:26952 pid:9538 tgid:9538 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
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
__flush_workqueue+0x3e2/0x1230 kernel/workqueue.c:4000
rds_tcp_listen_stop+0x104/0x150 net/rds/tcp_listen.c:331
rds_tcp_kill_sock net/rds/tcp.c:611 [inline]
rds_tcp_exit_net+0xcb/0x810 net/rds/tcp.c:634
ops_exit_list net/core/net_namespace.c:198 [inline]
ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:251
cleanup_net+0x408/0x890 net/core/net_namespace.c:682
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
3 locks held by kworker/0:1/10:
#0: ffff8880b843a458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:636
#1: ffff8880b8424088 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline]
#1: ffff8880b8424088 (psi_seq){-.-.}-{0:0}, at: __schedule+0x1861/0x5de0 kernel/sched/core.c:6955
#2: ffff8880b8425b18 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x127/0x1d0 kernel/time/timer.c:1004
1 lock held by khungtaskd/31:
#0: ffffffff8e5c1420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c1420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c1420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by syz-executor/5862:
#0: ffff88814d71c618 (sb_internal){.+.+}-{0:0}, at: evict+0x3e6/0x920 fs/inode.c:810
#1: ffff8880252a8950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444
1 lock held by syz-executor/5870:
#0: ffffffff8e5cc9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by getty/9208:
#0: ffff88814dc2e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900030002f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
3 locks held by kworker/u10:3/9538:
#0: ffff88801c6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc9000ba9fd10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
#2: ffffffff90372650 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:658
1 lock held by syz.3.766/9714:
#0: ffffffff90372650 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:566
1 lock held by syz.4.849/10188:
#0: ffffffff90372650 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:566
1 lock held by syz.0.970/10847:
#0: ffffffff90372650 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:566
1 lock held by syz.6.1069/11354:
#0: ffffffff8e5cc880 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3815
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U syzkaller #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf0e/0x1260 kernel/hung_task.c:491
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245