syzbot

INFO: task syz-executor:16048 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-[ 1759.725336][   T38] task:syz-executor    state:D stack:25104 pid:16048 tgid:16048 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x16ec/0x5620 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7564
 rwbase_write_lock+0x3da/0x730 kernel/locking/rwbase_rt.c:273
 rdma_dev_exit_net+0x92/0x350 drivers/infiniband/core/device.c:1132
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252
 setup_net+0x2f0/0x340 net/core/net_namespace.c:462
 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:579
 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234
 ksys_unshare+0x57d/0x9f0 kernel/fork.c:3242
 __do_sys_unshare kernel/fork.c:3316 [inline]
 __se_sys_unshare kernel/fork.c:3314 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3314
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4158efe127
RSP: 002b:00007ffd595fde58 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f4159175f40 RCX: 00007f4158efe127
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f41591767b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffd595fe098 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
4 locks held by ktimers/1/29:
1 lock held by khungtaskd/38:
 #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:2/822:
6 locks held by kworker/u8:12/3788:
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc9000ecf7c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc9000ecf7c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffff888021b62310 (&devlink->lock_key#8){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xbd0 drivers/net/netdevsim/dev.c:909
 #3: ffff8880372ac920 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #3: ffff8880372ac920 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:862 [inline]
 #3: ffff8880372ac920 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x1ad/0xbd0 drivers/net/netdevsim/dev.c:922
 #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
 #5: ffff88801a02ab58 (&barn->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #5: ffff88801a02ab58 (&barn->lock){+.+.}-{3:3}, at: barn_put_full_sheaf mm/slub.c:3120 [inline]
 #5: ffff88801a02ab58 (&barn->lock){+.+.}-{3:3}, at: __pcs_replace_empty_main+0x43e/0x720 mm/slub.c:4698
1 lock held by udevd/4967:
 #0: ffff888037bce480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
2 locks held by getty/5359:
 #0: ffff888036e0d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by kworker/1:3/5609:
8 locks held by kworker/u8:14/5861:
2 locks held by kworker/u8:15/6536:
4 locks held by kworker/u8:16/6565:
 #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90003a5fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90003a5fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
 #3: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x92/0x350 drivers/infiniband/core/device.c:1132
6 locks held by kworker/u8:5/10529:
3 locks held by kworker/1:6/14745:
5 locks held by syz.3.2663/15974:
4 locks held by kworker/u8:4/16036:
2 locks held by kworker/1:9/16043:
2 locks held by syz-executor/16048:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x92/0x350 drivers/infiniband/core/device.c:1132
2 locks held by syz-executor/16071:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x92/0x350 drivers/infiniband/core/device.c:1132
2 locks held by syz-executor/16096:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x92/0x350 drivers/infiniband/core/device.c:1132
3 locks held by syz-executor/16116:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16117:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16126:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16150:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16170:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16193:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16201:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16215:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16263:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16274:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16312:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16318:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16347:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16377:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by syz-executor/16387:
 #0: ffffffff8f3417e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8f09f060 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8f09f2a0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
3 locks held by dhcpcd-run-hook/16410:
1 lock held by syz-executor/16411:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 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:162 [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:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:-1 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x1d/0x80 kernel/kcov.c:217
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 68 23 a5 10 65 8b 35 89 23 a5 10 81 e6 00 00 ff 00 <ba> 00 01 00 00 23 91 e4 0b 00 00 89 d7 09 f7 74 11 85 f6 75 39 85
RSP: 0018:ffffc90000a3fba0 EFLAGS: 00000246
RAX: ffffffff89164328 RBX: 0000000000000001 RCX: ffff88801d6ebd80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffffff8ba75c80
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000100
R10: dffffc0000000000 R11: fffffbfff1f10dff R12: ffff888040420080
R13: ffff888040420040 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888126287000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f33edbac080 CR3: 000000000ddb6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 trace_qdisc_dequeue include/trace/events/qdisc.h:14 [inline]
 dequeue_skb net/sched/sch_generic.c:331 [inline]
 qdisc_restart net/sched/sch_generic.c:427 [inline]
 __qdisc_run+0x958/0x1570 net/sched/sch_generic.c:445
 qdisc_run include/net/pkt_sched.h:120 [inline]
 net_tx_action+0x806/0xc30 net/core/dev.c:5853
 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0x69/0x100 kernel/softirq.c:1151
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>