INFO: task syz.1.1577:11166 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1577      state:D
 stack:22712 pid:11166 tgid:11160 ppid:5843   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x9a/0x270
 wait_for_completion+0x2bf/0x5d0
 disable_device+0x1c6/0x320
 __ib_unregister_device+0x2cb/0x3f0
 ib_unregister_device_and_put+0xb8/0xf0
 nldev_dellink+0x2d1/0x320
 rdma_nl_rcv+0x6ae/0x980
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fab35f8ebe9
RSP: 002b:00007fab36ec1038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fab361b6090 RCX: 00007fab35f8ebe9
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000006
RBP: 00007fab36011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fab361b6128 R14: 00007fab361b6090 R15: 00007ffe22424198
 </TASK>
INFO: task syz.0.1703:11572 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1703      state:D stack:24584 pid:11572 tgid:11571 ppid:5848   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1360
 rdma_dev_change_netns+0x39/0x300
 rdma_dev_exit_net+0x203/0x340
 ops_undo_list+0x49a/0x990
 setup_net+0x2d3/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 copy_namespaces+0x438/0x4b0
 copy_process+0x1733/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f19a7f8ebe9
RSP: 002b:00007f19a8e44fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f19a81b5fa0 RCX: 00007f19a7f8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040001200
RBP: 00007f19a8011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f19a81b6038 R14: 00007f19a81b5fa0 R15: 00007ffc3bbe4038
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ea0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5672:
 #0: ffff888028d200a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:2/5853:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000355fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52adb0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff88803a4a8700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.1.1577/11166:
 #0: ffffffff99e66838 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff88803a4a8700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.0.1703/11572:
 #0: ffffffff8f52adb0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4a8700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.2358/13812:
 #0: ffffffff8f52adb0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4a8700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.2408/13996:
 #0: ffffffff8f52adb0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4a8700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.2617/14689:
 #0: ffffffff8f52adb0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4a8700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.2865/15534:
1 lock held by syz.6.2871/15553:
 #0: ffffffff8e19d448 (event_mutex){+.+.}-{4:4}, at: perf_trace_destroy+0x2e/0x150

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 15534 Comm: syz.6.2865 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:mod_memcg_lruvec_state+0x139/0x370
Code: 8b 7c 24 08 0f 87 e1 00 00 00 89 d8 48 b9 60 00 00 00 00 00 48 00 48 0f a3 c1 0f 83 bb 00 00 00 b9 01 00 00 00 31 c0 0f af cd <81> f9 00 20 00 00 41 bc ff 1f 00 00 44 0f 43 e1 41 c1 fc 0c 84 c0
RSP: 0018:ffffc9002176e6b0 EFLAGS: 00000006
RAX: 0000000000000001 RBX: 0000000000000016 RCX: 0000000000001000
RDX: 0000000000000001 RSI: ffffffff8b983be0 RDI: ffff8881107ddb00
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822aa009
R10: dffffc0000000000 R11: fffffbfff1f46fc7 R12: ffff888111783b88
R13: 0000000000000013 R14: 0000000000000001 R15: 0000607e5c0994d0
FS:  00007fb558bbb6c0(0000) GS:ffff8881a3c1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555571b115c8 CR3: 0000000060fa6000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 __lruvec_stat_mod_folio+0x1a0/0x2f0
 shmem_add_to_page_cache+0x8b3/0xba0
 shmem_alloc_and_add_folio+0x846/0xf60
 shmem_get_folio_gfp+0x59d/0x1660
 shmem_write_begin+0xf7/0x2b0
 generic_perform_write+0x2c5/0x900
 shmem_file_write_iter+0xf8/0x120
 __kernel_write_iter+0x428/0x910
 dump_user_range+0x8a0/0xc90
 elf_core_dump+0x337b/0x3990
 coredump_write+0x1169/0x1900
 vfs_coredump+0x1a4b/0x2ab0
 get_signal+0x1109/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 irqentry_exit_to_user_mode+0x81/0x120
 exc_page_fault+0x9f/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x2702dcf4
Code: Unable to access opcode bytes at 0x2702dcca.
RSP: 002b:0000200000000238 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fb557fb5fa0 RCX: 00007fb557d8ebe9
RDX: 00002000000000c0 RSI: 0000200000000230 RDI: 0000000002000000
RBP: 00007fb557e11e19 R08: 0000200000000280 R09: 0000200000000280
R10: 0000200000000240 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fb557fb6038 R14: 00007fb557fb5fa0 R15: 00007fff6e2cd258
 </TASK>
