INFO: task syz.3.2127:13536 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2127 state:D stack:27168 pid:13536 tgid:13535 ppid:5638 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1728
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1bf479cdd9
RSP: 002b:00007f1bf29f6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1bf4a15fa0 RCX: 00007f1bf479cdd9
RDX: 0000000020000000 RSI: 0000200000000140 RDI: 0000000000000005
RBP: 00007f1bf4832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1bf4a16038 R14: 00007f1bf4a15fa0 R15: 00007ffec3652788
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:6/739:
2 locks held by dhcpcd/5291:
2 locks held by getty/5387:
#0: ffff8880363290a0 (&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+0x45c/0x13a0 drivers/tty/n_tty.c:2211
7 locks held by kworker/0:4/5732:
#0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1: ffffc9000455fc40 ((work_completion)(&aux->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
#1: ffffc9000455fc40 ((work_completion)(&aux->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffffffff8e9e7dc0 (pack_mutex){+.+.}-{4:4}, at: bpf_prog_pack_free+0x35/0x420 kernel/bpf/core.c:988
#3: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#3: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: percpu_ref_tryget_many include/linux/percpu-refcount.h:241 [inline]
#3: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: percpu_ref_tryget+0x15/0x180 include/linux/percpu-refcount.h:266
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: get_non_dying_memcg_start mm/memcontrol.c:817 [inline]
#4: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: mod_memcg_state+0x48/0x190 mm/memcontrol.c:879
#5: ffff88813fe79618 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
#5: ffff88813fe79618 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
#6: ffff8880b863aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:652
4 locks held by kworker/u8:14/9368:
#0: ffff88801be8e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff88801be8e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1: ffffc900034ffc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
#1: ffffc900034ffc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffffffff8fdc0c28 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
#3: ffffffff8e962f38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
5 locks held by kworker/u8:17/9371:
2 locks held by syz.2.2065/13330:
#0: ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938
2 locks held by syz.3.2127/13536:
#0: ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1728
2 locks held by dhcpcd/17895:
#0: ffff8880530a0260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
#0: ffff8880530a0260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204
#1: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
=============================================
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 04/18/2026
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:162 [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+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9721 Comm: kworker/u8:21 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: krds_cp_wq#4/6 rds_connect_worker
RIP: 0010:rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:838 [inline]
RIP: 0010:class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
RIP: 0010:unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495
Code: 00 e8 01 9a 34 00 4c 8d 3d 00 00 00 00 48 c7 c7 60 cd 95 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 41 57 e8 5d bc 2a 00 <48> 83 c4 08 e8 14 b8 31 0a 85 c0 74 3a e8 bb e4 33 00 84 c0 75 31
RSP: 0018:ffffc900000078f0 EFLAGS: 00000286
RAX: 4cee019e81362600 RBX: ffffffff819091d8 RCX: 0000000080000101
RDX: 0000000054273802 RSI: ffffffff8e219861 RDI: ffffffff8c28ade0
RBP: dffffc0000000000 R08: ffffffff8176f256 R09: ffffffff8e95cd60
R10: ffffc90000007a18 R11: ffffffff81b0e910 R12: ffffc90000007a00
R13: 1ffff92000000f39 R14: ffffc900000079c8 R15: ffffffff8176f256
FS: 0000000000000000(0000) GS:ffff88812528d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe8fd28370 CR3: 000000007506a000 CR4: 00000000003526f0
Call Trace:
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+0x46/0x50 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:2689 [inline]
slab_free mm/slub.c:6250 [inline]
kmem_cache_free+0x182/0x650 mm/slub.c:6377
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
__inet6_bind+0x399/0xf60 net/ipv6/af_inet6.c:419
kernel_bind+0x13e/0x1c0 net/socket.c:3660
rds_tcp_conn_path_connect+0x53e/0x930 net/rds/tcp_connect.c:175
rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
kthread+0x388/0x470 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