INFO: task syz.2.2034:15761 blocked for more than 163 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2034 state:D stack:27464 pid:15761 tgid:15755 ppid:5830 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe6/0x5fa0 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
nfsd_nl_listener_set_doit+0xd5/0x1b20 fs/nfsd/nfsctl.c:1886
genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa54/0xc30 net/socket.c:2592
___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
__sys_sendmsg+0x170/0x220 net/socket.c:2678
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd85ff9aeb9
RSP: 002b:00007fd860e80028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd860216090 RCX: 00007fd85ff9aeb9
RDX: 0000000020008050 RSI: 00002000000050c0 RDI: 0000000000000007
RBP: 00007fd860008c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd860216128 R14: 00007fd860216090 R15: 00007ffc0e747258
INFO: task syz-executor:15816 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:23816 pid:15816 tgid:15816 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe6/0x5fa0 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1353
deactivate_locked_super+0xc1/0x1b0 fs/super.c:474
deactivate_super fs/super.c:507 [inline]
deactivate_super+0xe7/0x110 fs/super.c:503
cleanup_mnt+0x21f/0x450 fs/namespace.c:1318
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ea/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1b90f9c117
RSP: 002b:00007ffe8ec57248 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f1b9100471f RCX: 00007f1b90f9c117
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe8ec57300
RBP: 00007ffe8ec57300 R08: 00007ffe8ec58300 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe8ec58390
R13: 00007f1b9100471f R14: 00000000000978b2 R15: 00007ffe8ec583d0
INFO: task syz.1.2055:15833 blocked for more than 145 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2055 state:D stack:27032 pid:15833 tgid:15828 ppid:5823 task_flags:0x400140 flags:0x00080006
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe6/0x5fa0 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1353
deactivate_locked_super+0xc1/0x1b0 fs/super.c:474
deactivate_super fs/super.c:507 [inline]
deactivate_super+0xe7/0x110 fs/super.c:503
cleanup_mnt+0x21f/0x450 fs/namespace.c:1318
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ea/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdc1559aeb9
RSP: 002b:00007fdc1638e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fdc15816090 RCX: 00007fdc1559aeb9
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000200000000000
RBP: 00007fdc15608c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdc15816128 R14: 00007fdc15816090 R15: 00007ffe533896a8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:26/7983:
#0: ffff88801e74c148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc900033a7c98 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
2 locks held by getty/14117:
#0: ffff88814cc2b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000bd032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
2 locks held by syz.3.1993/15569:
#0: ffffffff904a2bd0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1596
2 locks held by syz.2.2034/15761:
#0: ffffffff904a2bd0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b20 fs/nfsd/nfsctl.c:1886
2 locks held by syz-executor/15816:
#0: ffff8880295e00e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880295e00e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880295e00e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880295e00e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz.1.2055/15833:
#0: ffff88803594c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88803594c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88803594c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88803594c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz-executor/15921:
#0: ffff888086c180e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888086c180e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888086c180e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff888086c180e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz.7.2133/16264:
#0: ffff8880303900e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880303900e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880303900e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880303900e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz-executor/17197:
#0: ffff8880335420e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880335420e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880335420e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880335420e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:503
#1: ffffffff8ea476a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
6 locks held by kworker/u8:36/17817:
1 lock held by syz.6.2506/18130:
1 lock held by syz.6.2519/18209:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xcc3/0xfe0 kernel/hung_task.c:515
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17817 Comm: kworker/u8:36 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: krdsd rds_connect_worker
RIP: 0010:__hlist_del include/linux/list.h:994 [inline]
RIP: 0010:hlist_del include/linux/list.h:1006 [inline]
RIP: 0010:__alloc_object lib/debugobjects.c:232 [inline]
RIP: 0010:pcpu_alloc+0x13a/0x350 lib/debugobjects.c:256
Code: 00 0f 85 0b 02 00 00 4d 89 65 00 4d 85 e4 74 25 48 b8 00 00 00 00 00 fc ff df 49 8d 7c 24 08 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 f9 01 00 00 4d 89 6c 24 08 48 b8 00 01 00 00 00 00 ad de 48
RSP: 0018:ffffc900033f77e8 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8880b843c7c0 RCX: 1ffffffff216f4f6
RDX: 1ffff1100f9faa16 RSI: ffffffff8bfa3520 RDI: ffff88807cfd50b0
RBP: ffff88809532be38 R08: 0000000000000000 R09: fffff5200067eefa
R10: 0000000000000206 R11: 0000000000000000 R12: ffff88807cfd50a8
R13: ffff8880b843c7c0 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881245e2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc62dde4198 CR3: 0000000032d5c000 CR4: 00000000003526f0
Call Trace:
alloc_object lib/debugobjects.c:458 [inline]
lookup_object_or_alloc.part.0+0xc7/0x4f0 lib/debugobjects.c:685
lookup_object_or_alloc lib/debugobjects.c:665 [inline]
__debug_object_init+0x2a9/0x3d0 lib/debugobjects.c:743
debug_hrtimer_init kernel/time/hrtimer.c:427 [inline]
debug_setup kernel/time/hrtimer.c:463 [inline]
hrtimer_setup+0x29/0x50 kernel/time/hrtimer.c:1665
tcp_init_sock+0x7f/0xc40 net/ipv4/tcp.c:445
tcp_v4_init_sock+0x15/0xb0 net/ipv4/tcp_ipv4.c:2477
inet_create net/ipv4/af_inet.c:386 [inline]
inet_create+0x94c/0x1060 net/ipv4/af_inet.c:254
__sock_create+0x339/0x860 net/socket.c:1605
rds_tcp_conn_path_connect+0x2d0/0x7f0 net/rds/tcp_connect.c:115
rds_connect_worker+0x1b4/0x2d0 net/rds/threads.c:176
process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246