INFO: tas
INFO: task syz.5.3468:21004 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.3468 state:D stack:25584 pid:21004 tgid:21003 ppid:18131 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7376
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
nfsd_nl_svc_export_get_reqs_dumpit+0xf7/0xc40 fs/nfsd/export.c:674
genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026
netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2347
__netlink_dump_start+0x589/0x7b0 net/netlink/af_netlink.c:2462
genl_family_rcv_msg_dumpit+0x213/0x310 net/netlink/genetlink.c:1075
genl_family_rcv_msg net/netlink/genetlink.c:1191 [inline]
genl_rcv_msg+0x5e1/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916
sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
__sock_sendmsg net/socket.c:818 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2715
___sys_sendmsg+0x2a5/0x360 net/socket.c:2769
__sys_sendmsg net/socket.c:2801 [inline]
__do_sys_sendmsg net/socket.c:2806 [inline]
__se_sys_sendmsg net/socket.c:2804 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f376b59e159
RSP: 002b:00007f376c464028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f376b825fa0 RCX: 00007f376b59e159
RDX: 0000000004044810 RSI: 0000200000000180 RDI: 000000000000000e
RBP: 00007f376b63506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f376b826038 R14: 00007f376b825fa0 R15: 00007ffeaa2c8478
Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#0:
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5373: 2, on CPU#0:
#0: ffff888035c7d0a0 (&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+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u8:44/12602: 4, last CPU#1:
#0: ffff88802135b940 ((wq_completion)krds_cp_wq#15/5){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88802135b940 ((wq_completion)krds_cp_wq#15/5){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88802135b940 ((wq_completion)krds_cp_wq#15/5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88802135b940 ((wq_completion)krds_cp_wq#15/5){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc9000382fc40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000382fc40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000382fc40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc9000382fc40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffff88807b221580 (&tc->t_conn_path_lock){+.+.}-{4:4}, at: rds_tcp_conn_path_connect+0x1cc/0x920 net/rds/tcp_connect.c:118
#3: ffff88803c260fe0 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
#3: ffff88803c260fe0 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: __inet6_bind+0x301/0xf30 net/ipv6/af_inet6.c:292
locks held by syz.3.2827/17816: 2, on CPU#1:
#0: ffffffff902b8ee8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f7c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x53d/0x1ab0 fs/nfsd/nfsctl.c:2057
locks held by syz.5.3468/21004: 3, on CPU#0:
#0: ffffffff902b8ee8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffff88807c4df6e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2426
#2: ffffffff8f09f7c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_svc_export_get_reqs_dumpit+0xf7/0xc40 fs/nfsd/export.c:674
locks held by syz.4.3755/22148: 2, on CPU#1:
#0: ffffffff902b8ee8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f7c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_expkey_set_reqs_doit+0xfe/0xaf0 fs/nfsd/export.c:561
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [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+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x480 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12602 Comm: kworker/u8:44 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: krds_cp_wq#15/5 rds_connect_worker
RIP: 0010:__inet6_bind+0x1b4/0xf30 net/ipv6/af_inet6.c:-1
Code: bf 01 00 00 00 89 ee e8 4a 62 3f f7 83 fd 01 75 0f e8 00 5e 3f f7 b8 ea ff ff ff e9 32 02 00 00 4c 89 64 24 38 e8 ec 5d 3f f7 <4c> 89 6c 24 30 49 89 dc 49 8d 6f 02 48 89 e8 48 c1 e8 03 48 b9 00
RSP: 0018:ffffc9000382f758 EFLAGS: 00000293
RAX: ffffffff8a888fc1 RBX: ffff88803c260d80 RCX: ffff888054bc1f40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff888054bc1f40 R09: 0000000000000002
R10: 000000000000c0fe R11: 0000000000000000 R12: ffff88803c261a00
R13: ffffc9000382f828 R14: 1ffff1100784c1b2 R15: ffffc9000382f820
FS: 0000000000000000(0000) GS:ffff888124ddc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b7f3ed158 CR3: 000000000eb48000 CR4: 00000000003526f0
Call Trace:
kernel_bind+0x13e/0x1c0 net/socket.c:3677
rds_tcp_conn_path_connect+0x53b/0x920 net/rds/tcp_connect.c:175
rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 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