INFO: task syz.2.248:7199 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.248 state:D stack:26080 pid:7199 tgid:7199 ppid:5835 task_flags:0x40044c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
wb_wait_for_completion+0x360/0x680 fs/fs-writeback.c:226
sync_inodes_sb+0x1c9/0xb40 fs/fs-writeback.c:2894
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:1722
ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7444
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
task_work_run+0x1d4/0x260 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6c5/0x2310 kernel/exit.c:971
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2dea5c2005
RSP: 002b:00007f2deb4d1f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f2dea7e5fa0 RCX: 00007f2dea5c2005
RDX: 00007f2deb4d1fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f2dea613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f2dea7e6038 R14: 00007f2dea7e5fa0 R15: 00007ffc14687b88
Showing all locks held in the system:
1 lock held by kdevtmpfs/26:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e13f8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:8/1139:
3 locks held by kworker/u8:11/2208:
#0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc90004fe7b80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by getty/5587:
#0: ffff8880351e60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:13/5969:
#0: ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647
#1: ffffc90004bffb80 ((work_completion)(&(&slave->notify_work)->work)){+.+.}-{0:0}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647
#2: ffff8880b86260d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline]
#2: ffff8880b86260d8 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1085
2 locks held by syz.2.248/7199:
#0: ffff88802ad1c0e0 (&type->s_umount_key#32){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802ad1c0e0 (&type->s_umount_key#32){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802ad1c0e0 (&type->s_umount_key#32){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
#1: ffff888025042820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline]
#1: ffff888025042820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1ad/0xb40 fs/fs-writeback.c:2892
5 locks held by kworker/u8:26/8491:
#0: ffff88801ba9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc90014087b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f5034d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670
#3: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x9e0 net/core/dev.c:13041
#4: ffffffff8e1453f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#4: ffffffff8e1453f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956
1 lock held by +}[@/9889:
#0: ffff88802ad1c0e0 (&type->s_umount_key#32){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff88802ad1c0e0 (&type->s_umount_key#32){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.8.823/10070:
#0: ffff88802ad1c0e0 (&type->s_umount_key#32){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff88802ad1c0e0 (&type->s_umount_key#32){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz-executor/10187:
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
1 lock held by syz-executor/10251:
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
1 lock held by syz.3.875/10341:
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: wext_ioctl_dispatch+0xa2/0x410 net/wireless/wext-core.c:1013
1 lock held by syz.3.875/10343:
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6964
1 lock held by syz.5.876/10345:
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f510b08 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b20 net/ipv4/devinet.c:1120
3 locks held by syz.4.877/10353:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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]
__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:363 [inline]
watchdog+0xe40/0xe90 kernel/hung_task.c:557
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 4e 2b 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 6684ec6eedebd000 RBX: ffffffff8197888a RCX: 6684ec6eedebd000
RDX: 0000000000000001 RSI: ffffffff8d99597b RDI: ffffffff8be075e0
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fa20e70
R13: 1ffff11003adeb70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125d2d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000032000 CR3: 000000007905e000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147