INFO: task kworker/u8:6:153 blocked for more than 143 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6 state:D stack:25608 pid:153 tgid:153 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
__flush_workqueue+0x3f7/0x1200 kernel/workqueue.c:4084
rxrpc_destroy_all_connections+0xf9/0x420 net/rxrpc/conn_object.c:477
rxrpc_exit_net+0x7b/0xc0 net/rxrpc/net_ns.c:113
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252
cleanup_net+0x499/0x920 net/core/net_namespace.c:702
process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
process_scheduled_works kernel/workqueue.c:3359 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.2.1480:12948 blocked for more than 143 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1480 state:D stack:26776 pid:12948 tgid:12943 ppid:5827 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
__flush_workqueue+0x3f7/0x1200 kernel/workqueue.c:4084
rxrpc_release_sock net/rxrpc/af_rxrpc.c:961 [inline]
rxrpc_release+0x2a7/0x6a0 net/rxrpc/af_rxrpc.c:992
__sock_release net/socket.c:662 [inline]
sock_release+0x91/0x1c0 net/socket.c:690
afs_open_socket+0x32f/0x3f0 fs/afs/rxrpc.c:117
afs_net_init+0x825/0xb00 fs/afs/main.c:116
ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
setup_net+0x118/0x3a0 net/core/net_namespace.c:446
copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:579
create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:130
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226
ksys_unshare+0x473/0xad0 kernel/fork.c:3173
__do_sys_unshare kernel/fork.c:3244 [inline]
__se_sys_unshare kernel/fork.c:3242 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:3242
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a17f9c819
RSP: 002b:00007f0a18e78028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f0a18216090 RCX: 00007f0a17f9c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000080
RBP: 00007f0a18032c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0a18216128 R14: 00007f0a18216090 R15: 00007ffe05f77e78
Showing all locks held in the system:
2 locks held by ksoftirqd/0/15:
#0: ffff8880b843b360 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:655 [inline]
#0: ffff8880b843b360 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:639
#1: ffff8880b8424648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
#1: ffff8880b8424648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2c11/0x6120 kernel/sched/core.c:6905
1 lock held by khungtaskd/30:
#0: ffffffff8e7e7760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e7760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e7760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:6/153:
#0: ffff88801c6b6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc90002fe7d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffffffff905fead0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
2 locks held by getty/5585:
#0: ffff888029a000a0 (&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+0x419/0x1500 drivers/tty/n_tty.c:2211
1 lock held by syz.2.1480/12948:
#0: ffffffff905fead0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
1 lock held by syz.3.1500/13033:
#0: ffffffff905fead0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
1 lock held by syz.5.1560/13366:
#0: ffffffff8e7f3180 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
1 lock held by syz.4.1604/13528:
#0: ffffffff905fead0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
1 lock held by syz.0.1626/13668:
#0: ffffffff905fead0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
2 locks held by syz.1.1642/13758:
#0: ffffffff905fead0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff8e7f3180 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
1 lock held by syz.6.1659/13865:
#0: ffffffff8e7f3180 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
1 lock held by syz.7.1667/13924:
#0: ffffffff8e7f3180 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
2 locks held by syz.9.1696/14113:
#0: ffffffff905fead0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff8e7f3180 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
2 locks held by syz.9.1696/14116:
#0: ffffffff905fead0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff8e7f3180 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
2 locks held by syz.8.1698/14144:
#0: ffffffff905fead0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff8e7f3180 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
7 locks held by syz-executor/14132:
#0: ffff8880353fe420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff888039ad2488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff888025af5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888025af5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb6f208 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
#4: ffff888029a2c130 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#4: ffff888029a2c130 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1166 [inline]
#4: ffff888029a2c130 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1364
#5: ffff888029a2b250 (&devlink->lock_key#6){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1e0 drivers/net/netdevsim/dev.c:1778
#6: ffffffff8e7f3180 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
1 lock held by syz.2.1694/14158:
#0: ffffffff905fead0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
4 locks held by syz-executor/14163:
#0: ffff8880353fe420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff8880986f7088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff888025af5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888025af5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb6f208 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/14173:
#0: ffff8880353fe420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff888071bf3888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff888025af5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888025af5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb6f208 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/14182:
#0: ffff8880353fe420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff88806515dc88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff888025af5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888025af5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb6f208 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/14193:
#0: ffff8880353fe420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff8880a0ad6888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff888025af5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888025af5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb6f208 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 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: 0 Comm: swapper/0 Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:__sanitizer_cov_trace_pc+0xb/0x70 kernel/kcov.c:213
Code: 5f 00 be 03 00 00 00 5b e9 c2 6e ec 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 a5 bc 05 12 <48> 8b 34 24 65 48 8b 15 81 bc 05 12 a9 00 01 ff 00 74 1b f6 c4 01
RSP: 0018:ffffc90000007de8 EFLAGS: 00000246
RAX: 0000000000000101 RBX: ffff88802bb3db80 RCX: ffffffff81c5fc1d
RDX: 1ffff110064f6c5f RSI: ffffffff81c5fc7e RDI: ffff8880327b62f8
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000001 R11: 000000000000a9dd R12: ffff8880327b5e40
R13: ffffffff8e4975c0 R14: ffffffff81ee1f5d R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124340000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f90d4a41bd0 CR3: 000000005a1ee000 CR4: 00000000003526f0
Call Trace:
free_signal_struct kernel/fork.c:765 [inline]
put_signal_struct kernel/fork.c:773 [inline]
__put_task_struct+0x2e6/0x590 kernel/fork.c:789
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869
handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 88 84 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 e0 1c 00 fb f4 fc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e407e00 EFLAGS: 00000246
RAX: 00000000003e8c05 RBX: ffffffff8e4975c0 RCX: ffffffff8b8eac75
RDX: 0000000000000000 RSI: ffffffff8de83ac6 RDI: ffffffff8c1b1e20
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed101708679d
R10: ffff8880b8433ceb R11: 0000000000000000 R12: 0000000000000000
R13: fffffbfff1c92eb8 R14: 0000000000000000 R15: ffffffff90da0610
arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
rest_init+0x251/0x260 init/main.c:760
start_kernel+0x47f/0x480 init/main.c:1210
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148