INFO: task syz.0.1494:13643 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1494 state:D stack:28408 pid:13643 tgid:13638 ppid:5836 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg net/socket.c:729 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2617
___sys_sendmsg+0x134/0x1d0 net/socket.c:2671
__sys_sendmsg+0x16d/0x220 net/socket.c:2703
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f939118eec9
RSP: 002b:00007f938f3d5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f93913e6270 RCX: 00007f939118eec9
RDX: 0000000000000080 RSI: 0000200000000140 RDI: 0000000000000004
RBP: 00007f9391211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f93913e6308 R14: 00007f93913e6270 R15: 00007ffd242e1898
INFO: task syz.1.1507:13701 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1507 state:D stack:26904 pid:13701 tgid:13698 ppid:5842 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
chrdev_open+0x231/0x6a0 fs/char_dev.c:414
do_dentry_open+0x97f/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1095
do_open fs/namei.c:3975 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4134
do_filp_open+0x20b/0x470 fs/namei.c:4161
do_sys_openat2+0x11b/0x1d0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9ce2b8eec9
RSP: 002b:00007f9ce0dd5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f9ce2de6090 RCX: 00007f9ce2b8eec9
RDX: 0000000000000001 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f9ce2c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9ce2de6128 R14: 00007f9ce2de6090 R15: 00007ffda2cbd688
Showing all locks held in the system:
3 locks held by kworker/0:0/9:
1 lock held by khungtaskd/31:
#0: ffffffff8e1c34a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e1c34a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e1c34a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
1 lock held by klogd/5197:
2 locks held by getty/5599:
#0: ffff88803090d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by kworker/u9:6/5847:
#0: ffff88802607b148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc9000418fd10 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
2 locks held by kworker/u8:16/11660:
#0: ffff888146ec0948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc9000deefd10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
3 locks held by kworker/u8:19/11663:
3 locks held by kworker/u8:30/13546:
2 locks held by kworker/u8:34/13550:
#0: ffff888146ec0948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc9000e06fd10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
2 locks held by syz.0.1494/13640:
#0: ffffffff8ff7df90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5e4e28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
2 locks held by syz.0.1494/13643:
#0: ffffffff8ff7df90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5e4e28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
4 locks held by syz.2.1505/13689:
1 lock held by syz.1.1507/13701:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.4.1513/13749:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.4.1513/13751:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.5.1520/13847:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.6.1521/13884:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.7.1523/13908:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
2 locks held by syz.8.1529/13945:
#0: ffff8880313b60e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880313b60e0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880313b60e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880313b60e0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e5e4e28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
1 lock held by syz.9.1537/14095:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.3.1538/14099:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.3.1538/14105:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.0.1542/14164:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.0.1542/14166:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.1.1549/14243:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.4.1554/14386:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.5.1550/14383:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.5.1550/14387:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz-executor/14479:
#0: ffffffff8feda948 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8feda948 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978
1 lock held by syz.6.1567/14486:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
1 lock held by syz.2.1569/14507:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: ptmx_open drivers/tty/pty.c:823 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xff/0x360 drivers/tty/pty.c:790
1 lock held by syz.2.1569/14508:
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8ee102a8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf90 drivers/tty/tty_io.c:2120
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf0e/0x1260 kernel/hung_task.c:491
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245