INFO: task syz.8.4682:26227 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.4682 state:D stack:27200 pid:26227 tgid:26226 ppid:16115 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7276
__schedule_loop kernel/sched/core.c:7353 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7368
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7425
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
nfsd_nl_threads_set_doit+0x2b9/0xc30 fs/nfsd/nfsctl.c:1690
genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2575
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline]
netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1364
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
__sock_sendmsg net/socket.c:815 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2713
___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
__sys_sendmsg net/socket.c:2799 [inline]
__do_sys_sendmsg net/socket.c:2804 [inline]
__se_sys_sendmsg net/socket.c:2802 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802
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: 0033:0x7f3f67f9e159
RSP: 002b:00007f3f68eea028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3f68225fa0 RCX: 00007f3f67f9e159
RDX: 0000000000040070 RSI: 0000200000000100 RDI: 0000000000000003
RBP: 00007f3f6803506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3f68226038 R14: 00007f3f68225fa0 R15: 00007ffde56d36a8
Showing all locks held in the system:
locks held by ksoftirqd/1/24: 2, last CPU#1:
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: local_lock_acquire include/linux/local_lock_internal.h:46 [inline]
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x3de/0x18b0 net/core/dev.c:6724
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: ip6_pol_route+0x163/0x14d0 net/ipv6/route.c:2290
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/5375: 2, on CPU#1:
#0: ffff888032b3d0a0 (&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/u8:35/24441: 2, on CPU#1:
#0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc9000e4d7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000e4d7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000e4d7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc9000e4d7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by syz.5.4584/25851: 2, on CPU#1:
#0: ffffffff902c3668 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f500 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2b9/0xc30 fs/nfsd/nfsctl.c:1690
locks held by syz.8.4682/26227: 2, on CPU#1:
#0: ffffffff902c3668 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f500 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2b9/0xc30 fs/nfsd/nfsctl.c:1690
locks held by syz.7.5026/28043: 2, on CPU#1:
#0: ffffffff902c3668 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f500 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xd20 fs/nfsd/nfsctl.c:1919
locks held by syz.1.5328/29491: 2, on CPU#1:
#0: ffffffff902c3668 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f09f500 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_svc_export_set_reqs_doit+0x132/0x1450 fs/nfsd/export.c:1056
locks held by syz.6.5220/29521: 1, last CPU#0:
#0: ffffffff9aee8560 (nfnl_subsys_ipset){+.+.}-{4:4}, at: call_ad+0x26c/0xb50 net/netfilter/ipset/ip_set_core.c:1766
locks held by syz-executor/29551: 2, last CPU#0:
#0: ffffffff90243ec8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x524/0x780 net/core/net_namespace.c:578
#1: ffffffff90252780 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d5/0x820 net/ipv4/ip_tunnel.c:1136
locks held by syz.3.5342/29566: 1, on CPU#1:
#0: ffffffff9aee8560 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline]
#0: ffffffff9aee8560 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa69/0x12b0 net/netfilter/nfnetlink.c:293
locks held by modprobe/29586: 2, last CPU#0:
#0: ffff88807e911d38 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline]
#0: ffff88807e911d38 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0 mm/mmap.c:1323
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by sed/29591: 1, last CPU#1:
#0: ffff88807f935cf8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#0: ffff88807f935cf8 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579
=============================================
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 07/24/2026
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: 24 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:lock_class_cache_is_valid kernel/locking/lockdep.c:978 [inline]
RIP: 0010:__lock_acquire+0xd7/0x2de0 kernel/locking/lockdep.c:5155
Code: c9 75 4f 48 c7 c1 d0 94 3b 94 48 89 c2 48 29 ca 48 c1 fa 03 48 b9 29 5c 8f c2 f5 28 5c 8f 48 0f af ca 48 0f a3 0d d9 67 f7 12 <73> 26 48 8b 0b 48 85 c9 74 1e ba 01 00 00 00 85 f6 75 09 8b 50 58
RSP: 0018:ffffc900001e7458 EFLAGS: 00000803
RAX: ffffffff943b9a48 RBX: ffffffff8ed5c8a0 RCX: 0000000000000007
RDX: 00000000000000af RSI: 0000000000000000 RDI: ffffffff8ed5c8a0
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc900001e7738 R11: ffffffff81b285f0 R12: ffffffff8ed5c8a0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124dd2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f99d2629048 CR3: 000000007853c000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2748 [inline]
__rcu_free_sheaf_prepare+0x12d/0x2a0 mm/slub.c:3009
rcu_free_sheaf+0x31/0x200 mm/slub.c:6052
rcu_do_batch kernel/rcu/tree.c:2650 [inline]
rcu_core+0x926/0x1260 kernel/rcu/tree.c:2919
handle_softirqs+0x226/0x860 kernel/softirq.c:645
run_ksoftirqd+0x36/0x60 kernel/softirq.c:1099
smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
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