INFO: task syz.3.1553:12002 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1553 state:D stack:26200 pid:12002 tgid:11999 ppid:5827 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410 fs/nfsd/nfsctl.c:1494
genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026
netlink_dump+0x722/0xe80 net/netlink/af_netlink.c:2325
__netlink_dump_start+0x5cb/0x7e0 net/netlink/af_netlink.c:2440
genl_family_rcv_msg_dumpit+0x213/0x310 net/netlink/genetlink.c:1075
genl_family_rcv_msg net/netlink/genetlink.c:1191 [inline]
genl_rcv_msg+0x5e8/0x7a0 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+0x80f/0x9b0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:721 [inline]
__sock_sendmsg net/socket.c:736 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2585
___sys_sendmsg+0x2a5/0x360 net/socket.c:2639
__sys_sendmsg net/socket.c:2671 [inline]
__do_sys_sendmsg net/socket.c:2676 [inline]
__se_sys_sendmsg net/socket.c:2674 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2674
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fad2ab9c799
RSP: 002b:00007fad2b9b8028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fad2ae16180 RCX: 00007fad2ab9c799
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 0000000000000047
RBP: 00007fad2ac32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fad2ae16218 R14: 00007fad2ae16180 R15: 00007ffc60ef85e8
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5584:
#0: ffff888032bd10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/5835:
#0: ffff8880273a5358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by udevd/5837:
#0: ffff88802713d358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
3 locks held by kworker/u8:16/8459:
#0: ffff88813fe54148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88813fe54148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc900045ffc40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc900045ffc40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffffffff8e764800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
2 locks held by syz.2.1379/11388:
#0: ffffffff8fc37a50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ea86788 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2b5/0x9a0 fs/nfsd/nfsctl.c:1607
3 locks held by syz.3.1553/12002:
#0: ffffffff8fc37a50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffff888022b736f0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404
#2: ffffffff8ea86788 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410 fs/nfsd/nfsctl.c:1494
1 lock held by syz-executor/17538:
#0: ffffffff8fbc9608 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8fbc9608 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978
2 locks held by syz.6.3013/17959:
#0: ffffffff8fbc9608 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fbc9608 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
#1: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
2 locks held by dhcpcd-run-hook/17994:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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: 17994 Comm: sed Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:unwind_next_frame+0x484/0x23c0 arch/x86/kernel/unwind_orc.c:520
Code: d2 84 c0 48 0f 45 d1 48 89 15 68 8f ac 11 48 85 d2 0f 84 40 02 00 00 4c 8d 62 04 4c 8d 6a 05 4c 89 e0 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 66 18 00 00 4c 89 e8 48 c1 e8 03 0f b6 04 28 84 c0 0f
RSP: 0018:ffffc90004ecf2b8 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffffffff9029e6bc RCX: ffffffff9029e6c0
RDX: ffffffff90a610fc RSI: ffffffff90a610cc RDI: ffffffff8c27ca20
RBP: dffffc0000000000 R08: 0000000000000009 R09: ffffffff8e75e620
R10: ffffc90004ecf3e8 R11: fffff520009d9e89 R12: ffffffff90a61100
R13: ffffffff90a61101 R14: ffffc90004ecf3e8 R15: ffffffff9029e6bc
FS: 0000000000000000(0000) GS:ffff888125555000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd208810368 CR3: 000000000e54c000 CR4: 00000000003526f0
Call Trace:
__unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
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
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5380
kmalloc_noprof include/linux/slab.h:950 [inline]
slab_free_hook mm/slub.c:2637 [inline]
slab_free mm/slub.c:6165 [inline]
kmem_cache_free+0x15b/0x630 mm/slub.c:6295
anon_vma_free mm/rmap.c:137 [inline]
__put_anon_vma+0x12b/0x2d0 mm/rmap.c:2909
put_anon_vma mm/internal.h:215 [inline]
unlink_anon_vmas+0x58b/0x730 mm/rmap.c:536
free_pgtables+0x836/0xb70 mm/memory.c:427
exit_mmap+0x490/0xa10 mm/mmap.c:1314
__mmput+0x118/0x430 kernel/fork.c:1175
exit_mm+0x168/0x220 kernel/exit.c:581
do_exit+0x6a2/0x23c0 kernel/exit.c:964
do_group_exit+0x21b/0x2d0 kernel/exit.c:1118
__do_sys_exit_group kernel/exit.c:1129 [inline]
__se_sys_exit_group kernel/exit.c:1127 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1127
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f929a4e06c5
Code: Unable to access opcode bytes at 0x7f929a4e069b.
RSP: 002b:00007ffe8d9c4578 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f929a5e1fe8 RCX: 00007f929a4e06c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f929a5e0680 R15: 00007f929a5e2000