INFO: task syz.4.13359:19607 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.13359 state:D stack:26728 pid:19607 tgid:19606 ppid:15021 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5820 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
nfsd_nl_cache_flush_doit+0xe2/0x1b0 fs/nfsd/nfsctl.c:2319
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:2576
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361
netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920
sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
__sock_sendmsg net/socket.c:818 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2715
___sys_sendmsg+0x2a5/0x360 net/socket.c:2769
__sys_sendmsg net/socket.c:2801 [inline]
__do_sys_sendmsg net/socket.c:2806 [inline]
__se_sys_sendmsg net/socket.c:2804 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804
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: 0033:0x7fbe7ed9f559
RSP: 002b:00007fbe7fd4e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fbe7f025fa0 RCX: 00007fbe7ed9f559
RDX: 0000000000000020 RSI: 0000200000000840 RDI: 0000000000000007
RBP: 00007fbe7ee36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbe7f026038 R14: 00007fbe7f025fa0 R15: 00007ffd88ad6708
Showing all locks held in the system:
locks held by khungtaskd/33: 1, last CPU#0:
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by udevd/4998: 2, last CPU#1:
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
#1: ffff8880b853bea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:677
locks held by getty/5387: 2, on CPU#1:
#0: ffff8880368c10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032432e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz.1.13222/19248: 2, on CPU#1:
#0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff9009e720 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x53d/0x1ab0 fs/nfsd/nfsctl.c:2057
locks held by syz.4.13359/19607: 2, on CPU#1:
#0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff9009e720 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_cache_flush_doit+0xe2/0x1b0 fs/nfsd/nfsctl.c:2319
locks held by syz.2.14075/22454: 1, last CPU#1:
#0: ffffffff9bf4aa40 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline]
#0: ffffffff9bf4aa40 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa69/0x12b0 net/netfilter/nfnetlink.c:293
locks held by syz.3.14080/22498: 2, last CPU#0:
#0: ffff888031ec6540 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
#0: ffff888031ec6540 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299
#1: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by syz.6.14089/22492: 1, on CPU#1:
#0: ffff888053ebccc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#0: ffff888053ebccc0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579
locks held by syz.6.14089/22500: 1, last CPU#0:
#0: ffff888053ebccc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
#0: ffff888053ebccc0 (&mm->mmap_lock){++++}-{4:4}, at: __mm_populate+0x182/0x390 mm/gup.c:1942
locks held by sed/22508: 1, last CPU#0:
#0: ffff88802cbd9bc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#0: ffff88802cbd9bc0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579
locks held by syz.0.14093/22510: 2, last CPU#1:
#0: ffffffff91276f20 (rtnl_mutex){+.+.}-{4:4}, at: ip6_mroute_setsockopt+0xc40/0xf80 net/ipv6/ip6mr.c:1760
#1: ffff8880b8528618 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:2079 [inline]
#1: ffff8880b8528618 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x466/0xa10 kernel/time/hrtimer.c:2132
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 33 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
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+0xfd2/0x1030 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: 22510 Comm: syz.0.14093 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:INIT_LIST_HEAD include/linux/list.h:53 [inline]
RIP: 0010:ipv6_mc_init_dev+0x38c/0xa50 net/ipv6/mcast.c:2859
Code: 31 c9 6a 00 e8 95 81 fe f6 48 83 c4 08 4c 8d b3 58 02 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 d4 76 94 f7 <4c> 89 b3 58 02 00 00 48 8d bb 60 02 00 00 48 89 f8 48 c1 e8 03 42
RSP: 0018:ffffc90003d87440 EFLAGS: 00000246
RAX: 1ffff11006959c4b RBX: ffff888034ace000 RCX: 0000000000000001
RDX: ffffffff9bf72920 RSI: ffffffff8d3497e0 RDI: ffff888034ace270
RBP: ffff888034ace5ac R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff22f8258 R12: ffff888061dc60a8
R13: dffffc0000000000 R14: ffff888034ace258 R15: 001fffffffc00000
FS: 00007fac2a1386c0(0000) GS:ffff888123b6b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558a5904e8 CR3: 00000000455fa000 CR4: 00000000003526f0
Call Trace:
ipv6_add_dev+0xccd/0x1400 net/ipv6/addrconf.c:460
addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3703
notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:86
call_netdevice_notifiers_extack net/core/dev.c:2351 [inline]
call_netdevice_notifiers net/core/dev.c:2365 [inline]
register_netdevice+0x1bfe/0x2280 net/core/dev.c:11711
ip6mr_reg_vif net/ipv6/ip6mr.c:712 [inline]
mif6_add+0x476/0xcc0 net/ipv6/ip6mr.c:935
ip6_mroute_setsockopt+0xe5e/0xf80 net/ipv6/ip6mr.c:1761
do_ipv6_setsockopt+0x34d/0x2960 net/ipv6/ipv6_sockglue.c:397
ipv6_setsockopt+0x59/0x170 net/ipv6/ipv6_sockglue.c:880
rawv6_setsockopt+0x276/0x5e0 net/ipv6/raw.c:1048
do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2399
__sys_setsockopt net/socket.c:2424 [inline]
__do_sys_setsockopt net/socket.c:2430 [inline]
__se_sys_setsockopt net/socket.c:2427 [inline]
__x64_sys_setsockopt+0x13d/0x1b0 net/socket.c:2427
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: 0033:0x7fac2919f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fac2a138028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fac29425fa0 RCX: 00007fac2919f559
RDX: 00000000000000ca RSI: 0000000000000029 RDI: 0000000000000003
RBP: 00007fac29236b20 R08: 000000000000000c R09: 0000000000000000
R10: 0000200000000040 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fac29426038 R14: 00007fac29425fa0 R15: 00007ffc3e1f1a58