INFO: task syz.4.1166:10111 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1166 state:D stack:27160 pid:10111 tgid:10110 ppid:5628 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
nfsd_nl_threads_set_doit+0x2bb/0xde0 fs/nfsd/nfsctl.c:1633
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1895
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0dd559cdd9
RSP: 002b:00007f0dd64e8028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0dd5815fa0 RCX: 00007f0dd559cdd9
RDX: 0000000004000080 RSI: 0000200000000100 RDI: 0000000000000004
RBP: 00007f0dd5632d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0dd5816038 R14: 00007f0dd5815fa0 R15: 00007ffdb72ef028
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:5/137:
#0: ffff8880b863aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:652
#1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffffffff8fdd02c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8fdd02c0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4206
#3: ffffffff9a6e5f18 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_assert_init+0x7f/0x3b0 lib/debugobjects.c:1024
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495
2 locks held by getty/5383:
#0: ffff8880358300a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by kworker/u8:15/7425:
2 locks held by syz.0.476/7779:
#0: ffffffff8fe3f7c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938
2 locks held by syz.4.1166/10111:
#0: ffffffff8fe3f7c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2bb/0xde0 fs/nfsd/nfsctl.c:1633
1 lock held by syz-executor/15281:
#0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
6 locks held by syz.6.3016/15462:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 15462 Comm: syz.6.3016 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:408
Code: f9 80 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 6c 34 ec fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 17 d1 67 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc9000456e2f0 EFLAGS: 00000002
RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 00000000000003f8 R08: ffff888025e90237 R09: 1ffff11004bd2046
R10: dffffc0000000000 R11: ffffffff8544c600 R12: dffffc0000000000
R13: ffffffff9a48f9a1 R14: ffffffff9a7a8880 R15: 0000000000000000
FS: 00007fcdf56e66c0(0000) GS:ffff888125287000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3dc51e9000 CR3: 000000007bb80000 CR4: 00000000003526f0
Call Trace:
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3217 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x140c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3357
console_emit_next_record kernel/printk/printk.c:3183 [inline]
console_flush_one_record kernel/printk/printk.c:3269 [inline]
console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
_printk+0xdd/0x130 kernel/printk/printk.c:2504
ib_get_eth_speed+0x468/0x7f0 drivers/infiniband/core/verbs.c:2065
rxe_query_port+0x93/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:62
__ib_query_port drivers/infiniband/core/device.c:2121 [inline]
ib_query_port+0x170/0x830 drivers/infiniband/core/device.c:2153
ib_setup_port_attrs+0x294/0x2380 drivers/infiniband/core/sysfs.c:1384
add_one_compat_dev+0x448/0x650 drivers/infiniband/core/device.c:978
add_compat_devs drivers/infiniband/core/device.c:1036 [inline]
enable_device_and_get+0x2b3/0x3e0 drivers/infiniband/core/device.c:1347
ib_register_device+0x110f/0x13e0 drivers/infiniband/core/device.c:1460
rxe_register_device+0x1e3/0x350 drivers/infiniband/sw/rxe/rxe_verbs.c:1543
rxe_net_add+0x81/0x110 drivers/infiniband/sw/rxe/rxe_net.c:623
rxe_newlink+0xf4/0x1c0 drivers/infiniband/sw/rxe/rxe.c:243
nldev_newlink+0x5bc/0x650 drivers/infiniband/core/nldev.c:1812
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+0x6d1/0xa10 drivers/infiniband/core/netlink.c:259
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1895
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcdf479cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcdf56e6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fcdf4a15fa0 RCX: 00007fcdf479cdd9
RDX: 0000000000004000 RSI: 0000200000000480 RDI: 0000000000000004
RBP: 00007fcdf4832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcdf4a16038 R14: 00007fcdf4a15fa0 R15: 00007ffc10624188