INFO: task kworker/u8:6:1105 blocked for more than 163 seconds.
Tainted: G U W I L XTNJ syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6 state:D stack:24104 pid:1105 tgid:1105 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
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
__debugfs_file_removed fs/debugfs/inode.c:770 [inline]
remove_one+0x312/0x420 fs/debugfs/inode.c:777
__simple_recursive_removal+0x15b/0x610 fs/libfs.c:631
debugfs_remove+0x5d/0x80 fs/debugfs/inode.c:800
nsim_dev_health_exit+0x3b/0xe0 drivers/net/netdevsim/health.c:227
nsim_dev_reload_destroy+0x144/0x4d0 drivers/net/netdevsim/dev.c:1710
nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:983
devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461
devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509
ops_pre_exit_list net/core/net_namespace.c:161 [inline]
ops_undo_list+0x187/0xab0 net/core/net_namespace.c:234
cleanup_net+0x41b/0x8b0 net/core/net_namespace.c:695
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.4.6411:24294 blocked for more than 165 seconds.
Tainted: G U W I L XTNJ syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.6411 state:D stack:27064 pid:24294 tgid:24288 ppid:15807 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
devlink_health_report+0x6b4/0xb00 net/devlink/health.c:680
nsim_dev_health_break_write+0x166/0x210 drivers/net/netdevsim/health.c:162
full_proxy_write+0x131/0x1a0 fs/debugfs/file.c:388
vfs_write+0x2a0/0x11d0 fs/read_write.c:684
ksys_write+0x12a/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdbf338f749
RSP: 002b:00007fdbf41a9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdbf35e6090 RCX: 00007fdbf338f749
RDX: 00000000000001ff RSI: 0000000000000000 RDI: 0000000000000002
RBP: 00007fdbf3413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdbf35e6128 R14: 00007fdbf35e6090 R15: 00007ffc99497a78
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
7 locks held by kworker/u8:4/60:
6 locks held by kworker/u8:6/1105:
#0: ffff88801ba9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc90003d2fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffffffff900d5010 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x8b0 net/core/net_namespace.c:669
#3: ffff888059d5e0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff888059d5e0e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#3: ffff888059d5e0e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506
#4: ffff888059d5f250 (&devlink->lock_key#4){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline]
#4: ffff888059d5f250 (&devlink->lock_key#4){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#4: ffff888059d5f250 (&devlink->lock_key#4){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506
#5: ffff888067d41568 (&sb->s_type->i_mutex_key#3/2){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1025 [inline]
#5: ffff888067d41568 (&sb->s_type->i_mutex_key#3/2){+.+.}-{4:4}, at: __simple_recursive_removal+0x354/0x610 fs/libfs.c:627
2 locks held by getty/20229:
#0: ffff88814d73d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000ac1e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
1 lock held by syz.3.5337/21024:
2 locks held by syz.1.6161/23554:
1 lock held by syz.3.6273/23886:
1 lock held by syz-executor/24249:
2 locks held by syz-executor/24263:
#0: ffffffff900eb448 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff900eb448 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3436
#1: ffffffff8e3cfb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
3 locks held by syz.4.6411/24294:
#0: ffff888033d0a2b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1232
#1: ffff888141ab0420 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738
#2: ffff888059d5f250 (&devlink->lock_key#4){+.+.}-{4:4}, at: devlink_health_report+0x6b4/0xb00 net/devlink/health.c:680
2 locks held by syz.1.7148/26572:
2 locks held by syz.3.7175/26647:
2 locks held by syz.3.7183/26676:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U W I L XTNJ syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [W]=WARN, [I]=FIRMWARE_WORKAROUND, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf3f/0x1170 kernel/hung_task.c:495
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 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: 24500 Comm: kworker/u8:5 Tainted: G U W I L XTNJ syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [W]=WARN, [I]=FIRMWARE_WORKAROUND, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: krdsd rds_connect_worker
RIP: 0010:lock_release+0x0/0x2f0 kernel/locking/lockdep.c:5876
Code: 8b 4c 24 20 44 8b 44 24 1c 44 8b 4c 24 18 4c 8b 54 24 10 44 8b 5c 24 0c eb 8c 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 41 55 41 54 49 89 f4 53 48 89 fb 48 83 ec
RSP: 0018:ffffc90000007320 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff92000000e65 RCX: ffffffff89bce202
RDX: ffff888027fc9e40 RSI: ffffffff89bce199 RDI: ffffffff8e3c45e0
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880a244f900
R13: ffff888054394900 R14: ffffc90000007358 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124a0d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2721a65f98 CR3: 000000000e182000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
ip_route_output_key_hash+0x13e/0x2b0 net/ipv4/route.c:2706
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2932
inet_csk_route_req+0x72e/0xd60 net/ipv4/inet_connection_sock.c:817
tcp_v4_route_req+0x389/0x460 net/ipv4/tcp_ipv4.c:1703
tcp_conn_request+0xfeb/0x34e0 net/ipv4/tcp_input.c:7454
tcp_v4_conn_request net/ipv4/tcp_ipv4.c:1741 [inline]
tcp_v4_conn_request+0xc5/0x310 net/ipv4/tcp_ipv4.c:1735
tcp_v6_conn_request+0x33c/0x510 net/ipv6/tcp_ipv6.c:1330
tcp_rcv_state_process+0xa64/0x6490 net/ipv4/tcp_input.c:6942
tcp_v4_do_rcv+0x68e/0x10a0 net/ipv4/tcp_ipv4.c:1954
tcp_v4_rcv+0x4204/0x4db0 net/ipv4/tcp_ipv4.c:2364
ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:239
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:260
dst_input include/net/dst.h:474 [inline]
ip_rcv_finish net/ipv4/ip_input.c:453 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:573
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6079
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6192
process_backlog+0x439/0x15e0 net/core/dev.c:6544
__napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7594
napi_poll net/core/dev.c:7657 [inline]
net_rx_action+0x97f/0xef0 net/core/dev.c:7784
handle_softirqs+0x219/0x8e0 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xb2/0xf0 kernel/softirq.c:510
__local_bh_enable_ip+0x100/0x120 kernel/softirq.c:450
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:936 [inline]
__dev_queue_xmit+0xb06/0x4490 net/core/dev.c:4790
dev_queue_xmit include/linux/netdevice.h:3365 [inline]
neigh_hh_output include/net/neighbour.h:531 [inline]
neigh_output include/net/neighbour.h:545 [inline]
ip_finish_output2+0xc38/0x21a0 net/ipv4/ip_output.c:237
__ip_finish_output.part.0+0x1b4/0x350 net/ipv4/ip_output.c:315
__ip_finish_output net/ipv4/ip_output.c:303 [inline]
ip_finish_output net/ipv4/ip_output.c:325 [inline]
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip_output+0x35f/0xa90 net/ipv4/ip_output.c:438
dst_output include/net/dst.h:464 [inline]
ip_local_out net/ipv4/ip_output.c:131 [inline]
__ip_queue_xmit+0x1bee/0x2330 net/ipv4/ip_output.c:534
__tcp_transmit_skb+0x2caf/0x44d0 net/ipv4/tcp_output.c:1628
tcp_transmit_skb net/ipv4/tcp_output.c:1646 [inline]
tcp_connect+0x2f34/0x5210 net/ipv4/tcp_output.c:4330
tcp_v4_connect+0x1588/0x1c10 net/ipv4/tcp_ipv4.c:347
__inet_stream_connect+0x915/0xf50 net/ipv4/af_inet.c:679
inet_stream_connect+0x57/0xa0 net/ipv4/af_inet.c:750
kernel_connect+0x107/0x180 net/socket.c:3672
rds_tcp_conn_path_connect+0x43e/0x7f0 net/rds/tcp_connect.c:176
rds_connect_worker+0x1af/0x2c0 net/rds/threads.c:176
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245