INFO: task syz.3.3759:23792 blocked for more than 143 seconds.
Tainted: G U I 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3759 state:D stack:27640 pid:23792 tgid:23791 ppid:16980 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746
nfsd_nl_threads_set_doit+0x698/0xbf0 fs/nfsd/nfsctl.c:1629
genl_family_rcv_msg_doit+0x206/0x2f0 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+0x16a/0x440 net/netlink/af_netlink.c:2534
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2566
___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
__sys_sendmsg+0x16d/0x220 net/socket.c:2652
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbd1978e969
RSP: 002b:00007fbd1a5cd038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fbd199b5fa0 RCX: 00007fbd1978e969
RDX: 0000000000040040 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fbd19810ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbd199b5fa0 R15: 00007ffe499b91b8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764
3 locks held by kworker/1:1/47:
#0: ffff88801b480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc90000b87d18 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffffffff8e3ca840 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3774
2 locks held by kworker/u9:3/15537:
#0: ffff888025cae948 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000cf07d18 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
2 locks held by getty/22637:
#0: ffff888035b3a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000a8632f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by syz.4.3675/23347:
#0: ffffffff901c8690 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7cc128 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x698/0xbf0 fs/nfsd/nfsctl.c:1629
2 locks held by syz-executor/23607:
#0: ffff88807e1c20e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88807e1c20e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88807e1c20e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88807e1c20e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7cc128 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz.3.3759/23792:
#0: ffffffff901c8690 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7cc128 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x698/0xbf0 fs/nfsd/nfsctl.c:1629
2 locks held by syz-executor/24056:
#0: ffff888029b240e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff888029b240e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff888029b240e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff888029b240e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7cc128 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U I 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 PREEMPT(full)
Tainted: [U]=USER, [I]=FIRMWARE_WORKAROUND
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xf70/0x12c0 kernel/hung_task.c:437
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
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: 47 Comm: kworker/1:1 Tainted: G U I 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 PREEMPT(full)
Tainted: [U]=USER, [I]=FIRMWARE_WORKAROUND
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
Workqueue: events free_obj_work
RIP: 0010:__orc_find+0x92/0xf0 arch/x86/kernel/unwind_orc.c:99
Code: 48 c1 ea 03 0f b6 34 0a 48 89 da 83 e2 07 83 c2 03 40 38 f2 7c 05 40 84 f6 75 4b 48 63 13 48 01 da 49 39 d5 73 af 4c 8d 63 fc <49> 39 ec 73 b2 4d 29 f7 49 c1 ff 02 4b 8d 14 7f 48 8d 04 50 48 83
RSP: 0018:ffffc90000b876d8 EFLAGS: 00000283
RAX: ffffffff912732ec RBX: ffffffff909f985c RCX: dffffc0000000000
RDX: ffffffff821f2db2 RSI: 0000000000000000 RDI: ffffffff909f982c
RBP: ffffffff909f9850 R08: ffffffff91273352 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000011f2d R12: ffffffff909f9858
R13: ffffffff821f2d7a R14: ffffffff909f982c R15: ffffffff909f984c
FS: 0000000000000000(0000) GS:ffff888124aec000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f520e77d2d8 CR3: 0000000012fce000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
unwind_next_frame+0x2ec/0x20a0 arch/x86/kernel/unwind_orc.c:494
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2380 [inline]
slab_free mm/slub.c:4642 [inline]
kmem_cache_free+0x2d4/0x4d0 mm/slub.c:4744
free_object_list.isra.0+0xf8/0x2a0 lib/debugobjects.c:326
free_obj_work+0x18c/0x390 lib/debugobjects.c:513
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245