INFO: task syz.4.111:6338 blocked for more than 144 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.111 state:D stack:26328 pid:6338 tgid:6338 ppid:5859 task_flags:0x40044c flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2834
sync_filesystem+0x17a/0x230 fs/sync.c:64
generic_shutdown_super+0x6f/0x2c0 fs/super.c:622
kill_block_super+0x44/0x90 fs/super.c:1766
ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7395
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:961
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa33f3c1465
RSP: 002b:00007fa340245f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007fa33f5d5fa0 RCX: 00007fa33f3c1465
RDX: 00007fa340245fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa33f411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007fa33f5d6038 R14: 00007fa33f5d5fa0 R15: 00007ffde2639bf8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:2/973:
#0: ffff88801a478d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801a478d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90003757bc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90003757bc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
2 locks held by kworker/u8:7/2939:
4 locks held by kworker/u8:8/2957:
#0: ffff888142ea5148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888142ea5148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000b207bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000b207bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff8880762bcb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
#2: ffff8880762bcb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1786 [inline]
#2: ffff8880762bcb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024
#3: ffff8880577c8270 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x765/0x1740 fs/ext4/inode.c:810
3 locks held by kworker/u8:11/6229:
#0: ffff88814cd42948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88814cd42948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000abc7bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000abc7bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
2 locks held by syz.4.111/6338:
#0: ffff8880762ba0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880762ba0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880762ba0e0 (&type->s_umount_key#31){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
#1: ffff888024a8c7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff888024a8c7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2832
2 locks held by getty/7559:
#0: ffff888033a130a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003f132f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by kworker/u8:20/7657:
#0: ffff88801fb44948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801fb44948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9001f987bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9001f987bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
5 locks held by kworker/u8:24/7661:
#0: ffff88801b2f6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801b2f6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9001f9c7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9001f9c7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8f52d090 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658
#3: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:172 [inline]
#3: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:247
#4: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#4: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
3 locks held by kworker/u8:25/7663:
#0: ffff88801a481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801a481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9001f9d7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9001f9d7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by syz-executor/11193:
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5027
3 locks held by syz-executor/11296:
#0: ffffffff8f59f570 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8f59f388 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
#1: ffffffff8f59f388 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
#1: ffffffff8f59f388 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209
#2: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: wg_set_device+0x15b/0x1fe0 drivers/net/wireguard/netlink.c:514
1 lock held by syz-executor/11463:
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
1 lock held by syz-executor/11525:
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1df0 drivers/net/tun.c:3075
2 locks held by syz.5.1511/11576:
1 lock held by syz-executor/11579:
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978
1 lock held by syz.8.1517/11601:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:kasan_check_range+0x1dc/0x2c0 mm/kasan/generic.c:189
Code: 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 b8 00 00 00 49 ff c3 49 ff cc 75 ee 5b 41 5c 41 5d 41 5e 41 5f <5d> e9 b9 27 ed fe cc 45 84 ff 75 63 41 f7 c7 00 ff 00 00 75 5f 41
RSP: 0018:ffffc90000197dd8 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81c76778
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fa3a530
RBP: ffffc90000197f20 R08: ffffffff8fa3a537 R09: 1ffffffff1f474a6
R10: dffffc0000000000 R11: fffffbfff1f474a7 R12: ffffffff8fa3a530
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110039d9b40
FS: 0000000000000000(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000348030 CR3: 0000000076f87000 CR4: 0000000000350ef0
Call Trace:
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
cpumask_test_cpu include/linux/cpumask.h:646 [inline]
cpu_online include/linux/cpumask.h:1205 [inline]
trace_irq_disable+0x28/0x110 include/trace/events/preemptirq.h:36
do_idle+0x119/0x510 kernel/sched/idle.c:310
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147