INFO: task kworker/u8:9:17412 blocked for more than 144 seconds.
      Not tainted 6.15.0-syzkaller-01972-g914873bc7df9 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9    state:D stack:22584 pid:17412 tgid:17412 ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5392 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6781
 __schedule_loop kernel/sched/core.c:6859 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6874
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6931
 __mutex_lock_common kernel/locking/mutex.c:678 [inline]
 __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746
 rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1666
 rdma_dev_exit_net+0x203/0x340 drivers/infiniband/core/device.c:1144
 ops_exit_list net/core/net_namespace.c:172 [inline]
 cleanup_net+0x717/0xbd0 net/core/net_namespace.c:654
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz.2.3242:19866 blocked for more than 144 seconds.
      Not tainted 6.15.0-syzkaller-01972-g914873bc7df9 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3242      state:D stack:23768 pid:19866 tgid:19858 ppid:5816   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5392 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6781
 __schedule_loop kernel/sched/core.c:6859 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6874
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148
 disable_device+0x1c6/0x320 drivers/infiniband/core/device.c:1288
 __ib_unregister_device+0x2cb/0x3f0 drivers/infiniband/core/device.c:1518
 ib_unregister_device_and_put+0xb8/0xf0 drivers/infiniband/core/device.c:1583
 nldev_dellink+0x2d1/0x320 drivers/infiniband/core/nldev.c:1826
 rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline]
 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
 rdma_nl_rcv+0x6bf/0x9a0 drivers/infiniband/core/netlink.c:259
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:727
 ____sys_sendmsg+0x505/0x830 net/socket.c:2566
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
 __sys_sendmsg net/socket.c:2652 [inline]
 __do_sys_sendmsg net/socket.c:2657 [inline]
 __se_sys_sendmsg net/socket.c:2655 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x220 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f15c3d8e969
RSP: 002b:00007f15c1bd5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f15c3fb6160 RCX: 00007f15c3d8e969
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000008
RBP: 00007f15c3e10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f15c3fb6160 R15: 00007ffd5339c448
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df3c9a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3c9a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8df3c9a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5578:
 #0: ffff888030f810a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fee2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/u8:5/14841:
 #0: ffff88801a0a0018 (&pool->lock){-.-.}-{2:2}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a0a0018 (&pool->lock){-.-.}-{2:2}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc90003a67c60 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90003a67c60 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffffffff8df3c9a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8df3c9a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8df3c9a0 (rcu_read_lock){....}-{1:3}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 #2: ffffffff8df3c9a0 (rcu_read_lock){....}-{1:3}, at: batadv_nc_worker+0xd2/0x610 net/batman-adv/network-coding.c:719
4 locks held by kworker/u8:9/17412:
 #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc90005127c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90005127c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffffffff8f2e4790 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608
 #3: ffff88805a8946d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1666
2 locks held by syz.2.3242/19866:
 #0: ffffffff99bcaed8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:164 [inline]
 #0: ffffffff99bcaed8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
 #0: ffffffff99bcaed8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x316/0x9a0 drivers/infiniband/core/netlink.c:259
 #1: ffff88805a8946d0 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0 drivers/infiniband/core/device.c:1514

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-01972-g914873bc7df9 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:437
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:148
 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: 9535 Comm: kworker/u8:8 Not tainted 6.15.0-syzkaller-01972-g914873bc7df9 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0xad3/0xd20 kernel/locking/lockdep.c:5248
Code: 01 00 00 4c 89 f6 89 ea 4c 89 f9 e8 17 38 00 00 85 c0 0f 84 e4 01 00 00 41 f6 46 22 10 75 2e 48 8b 1c 24 4c 89 bb e0 0a 00 00 <8b> 83 e8 0a 00 00 ff c0 89 83 e8 0a 00 00 83 f8 30 0f 83 64 01 00
RSP: 0018:ffffc9001a5af990 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff88805a92da00 RCX: 2a677b1ede717600
RDX: 0000000000000000 RSI: ffff88805a92e540 RDI: ffff88805a92da00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b24b3a2
R10: dffffc0000000000 R11: ffffffff8b24b2d0 R12: 00000000773e543c
R13: ffff88805a92e4f0 R14: ffff88805a92e540 R15: a54c6a9eb7305562
FS:  0000000000000000(0000) GS:ffff8881261c7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564f81b7a168 CR3: 000000000dd36000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>