INFO: task syz.1.4062:25439 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.4062 state:D stack:24536 pid:25439 tgid:25438 ppid:18735 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 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+0x7fe/0x1300 kernel/locking/mutex.c:776
nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1736
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x232/0x4b0 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+0x80f/0x9b0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa68/0xad0 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b5ef9aeb9
RSP: 002b:00007f8b5ff04028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8b5f215fa0 RCX: 00007f8b5ef9aeb9
RDX: 0000000004008090 RSI: 0000200000000140 RDI: 0000000000000009
RBP: 00007f8b5f008c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b5f216038 R14: 00007f8b5f215fa0 R15: 00007ffda684f918
Showing all locks held in the system:
2 locks held by kworker/u8:1/13:
#0: ffff88813fe69148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813fe69148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc90000127bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90000127bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
1 lock held by khungtaskd/31:
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by dhcpcd/5492:
#0: ffff8880367c86f0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404
#1: ffffffff8f9ac088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f9ac088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826
2 locks held by getty/5587:
#0: ffff88814eadf0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by syz.3.3229/19768:
#0: ffffffff8fa1a130 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e879368 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2cb/0x960 fs/nfsd/nfsctl.c:1596
2 locks held by syz.1.4062/25439:
#0: ffffffff8fa1a130 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e879368 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1736
3 locks held by kworker/u8:0/28760:
#0: ffff88814d9cb148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814d9cb148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc9000d197bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000d197bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffffffff8f9ac088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f9ac088 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4194
2 locks held by syz.0.5224/461:
#0: ffff888045296f48 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff888045296f48 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
#0: ffff888045296f48 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
#1: ffff888034172260 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline]
#1: ffff888034172260 (sk_lock-AF_CAN){+.+.}-{0:0}, at: bcm_release+0x1cd/0x940 net/can/bcm.c:1601
1 lock held by syz.4.5233/505:
#0: ffffffff8f9ac088 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f9ac088 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
2 locks held by syz.6.5237/522:
#0: ffffffff8f9ac088 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f9ac088 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
#1: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:956
1 lock held by syz.5.5238/530:
#0: ffffffff8f9ac088 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3078
1 lock held by syz.5.5238/534:
#0: ffff88807a5868d8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3b/0x100 net/netfilter/nf_tables_api.c:11559
1 lock held by modprobe/561:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 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: 565 Comm: modprobe Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:check_preemption_disabled+0x1/0xe0 lib/smp_processor_id.c:13
Code: 20 39 07 8c 48 c7 c6 60 39 07 8c eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 53 65 8b 05 c7 96 5b 07 65 8b 0d bc 96 5b 07 f7 c1 ff
RSP: 0000:ffffc9001475f570 EFLAGS: 00000282
RAX: ffffffff8236f41b RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff888024693d00 RSI: ffffffff8c073960 RDI: ffffffff8c073920
RBP: ffffc9001475f6e8 R08: ffffffff8236f3ea R09: ffffffff8e55a360
R10: ffff888024694600 R11: ffffffff81afb170 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8236f3ea R15: ffffea0001fa4e00
FS: 00007f1909452c80(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005618d4f042b8 CR3: 00000000a10ae000 CR4: 00000000003526f0
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:751
rcu_read_lock include/linux/rcupdate.h:868 [inline]
__update_page_owner_handle+0x94/0x570 mm/page_owner.c:255
__set_page_owner+0x10a/0x4c0 mm/page_owner.c:342
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884
prep_new_page mm/page_alloc.c:1892 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3945
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
folio_alloc_mpol_noprof mm/mempolicy.c:2505 [inline]
vma_alloc_folio_noprof+0xea/0x210 mm/mempolicy.c:2540
folio_prealloc mm/memory.c:-1 [inline]
alloc_anon_folio mm/memory.c:5168 [inline]
do_anonymous_page mm/memory.c:5225 [inline]
do_pte_missing+0x15a4/0x37a0 mm/memory.c:4402
handle_pte_fault mm/memory.c:6276 [inline]
__handle_mm_fault mm/memory.c:6414 [inline]
handle_mm_fault+0x1b8c/0x32a0 mm/memory.c:6583
do_user_addr_fault+0xa73/0x1360 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f19095b3d34
Code: 8d 34 19 49 39 d0 49 89 70 60 0f 95 c2 48 29 d8 48 83 c1 10 0f b6 d2 48 83 c8 01 48 c1 e2 02 48 09 da 48 83 ca 01 48 89 51 f8 <48> 89 46 08 48 89 cf 4c 89 e6 48 89 4c 24 08 e8 18 c7 ff ff 48 8b
RSP: 002b:00007ffdeb9d8e60 EFLAGS: 00010206
RAX: 000000000001fd51 RBX: 00000000000009b0 RCX: 00005618d4f03910
RDX: 00000000000009b1 RSI: 00005618d4f042b0 RDI: 0000000000000000
RBP: ffffffffffffffc0 R08: 00007f19096ecac0 R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000246 R12: 00000000000009a0
R13: 0000000000000000 R14: 0000000000000099 R15: 00007f19096ecb20
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog