INFO: task syz.0.7587:23122 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc4-next-20250704-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.7587      state:D stack:22904 pid:23122 tgid:23121 ppid:6068   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5318 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6701
 __schedule_loop kernel/sched/core.c:6779 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6794
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
 disable_device+0x1c6/0x320 drivers/infiniband/core/device.c:1298
 __ib_unregister_device+0x2cb/0x3f0 drivers/infiniband/core/device.c:1528
 ib_unregister_device_and_put+0xb8/0xf0 drivers/infiniband/core/device.c:1593
 nldev_dellink+0x2d1/0x320 drivers/infiniband/core/nldev.c:1827
 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+0x6ae/0x980 drivers/infiniband/core/netlink.c:259
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f852258e929
RSP: 002b:00007f85203f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f85227b5fa0 RCX: 00007f852258e929
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000003
RBP: 00007f8522610b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f85227b5fa0 R15: 00007ffe78f67b08
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e53bf60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e53bf60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e53bf60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by kworker/u8:3/49:
 #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
 #1: ffff8880b8623f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39a/0x6d0 kernel/sched/psi.c:991
4 locks held by kworker/u8:4/59:
 #0: ffff88801b6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #0: ffff88801b6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
 #1: ffffc9000210fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
 #1: ffffc9000210fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
 #2: ffffffff8f929f70 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658
 #3: ffff88807bc206e0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1676
2 locks held by getty/5609:
 #0: ffff88814d9f80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5835:
 #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
2 locks held by syz.0.7587/23122:
 #0: ffffffff9a2e3018 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:164 [inline]
 #0: ffffffff9a2e3018 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
 #0: ffffffff9a2e3018 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980 drivers/infiniband/core/netlink.c:259
 #1: ffff88807bc206e0 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0 drivers/infiniband/core/device.c:1524

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-next-20250704-syzkaller #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:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14022 Comm: ipvs-e:9:0 Not tainted 6.16.0-rc4-next-20250704-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__rb_erase_color+0x0/0xa70 lib/rbtree.c:412
Code: ff 4c 89 f7 e8 01 cb a9 f6 e9 ab fd ff ff cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 48 89 54 24
RSP: 0018:ffffc90004b2f5f0 EFLAGS: 00000086
RAX: 1ffff11004b26012 RBX: 0000000000155cc0 RCX: 1ffff11005ed3001
RDX: ffffffff8195c830 RSI: ffff8880b863a088 RDI: ffff888025930090
RBP: ffff8880259300b8 R08: ffffffff8fe37f37 R09: 1ffffffff1fc6fe6
R10: dffffc0000000000 R11: fffffbfff1fc6fe7 R12: ffff8880b863a040
R13: 1ffff11004b26017 R14: ffff8880244b8080 R15: ffff8880259300b0
FS:  0000000000000000(0000) GS:ffff8881257af000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5adc17f2d8 CR3: 000000000e336000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rb_erase_augmented include/linux/rbtree_augmented.h:331 [inline]
 rb_erase_augmented_cached include/linux/rbtree_augmented.h:340 [inline]
 __dequeue_entity+0x87d/0xc60 kernel/sched/fair.c:859
 set_next_entity+0xf7/0x500 kernel/sched/fair.c:5472
 pick_next_task_fair+0x94d/0xba0 kernel/sched/fair.c:8825
 __pick_next_task+0xe4/0x450 kernel/sched/core.c:5962
 pick_next_task kernel/sched/core.c:-1 [inline]
 __schedule+0x6fe/0x4d00 kernel/sched/core.c:6654
 __schedule_loop kernel/sched/core.c:6779 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6794
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 ip_vs_estimation_kthread+0x2a31/0x3a00 net/netfilter/ipvs/ip_vs_est.c:209
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>