INFO: task syz.6.1583:12308 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.1583 state:D stack:25912 pid:12308 tgid:12308 ppid:8683 task_flags:0x400040 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
request_wait_answer+0x553/0x7d0 fs/fuse/dev.c:585
__fuse_request_send fs/fuse/dev.c:599 [inline]
__fuse_simple_request+0x4d9/0xe20 fs/fuse/dev.c:693
fuse_simple_request fs/fuse/fuse_i.h:1263 [inline]
fuse_flush+0x4c7/0x6b0 fs/fuse/file.c:494
filp_flush+0x115/0x1c0 fs/open.c:1533
filp_close+0x1c/0x30 fs/open.c:1546
__range_close fs/file.c:790 [inline]
__do_sys_close_range+0x39b/0x730 fs/file.c:849
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc279d8f749
RSP: 002b:00007ffdfcb83ef8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007fc279fe7da0 RCX: 00007fc279d8f749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fc279fe7da0 R08: 00000000000001f4 R09: 0000001efcb841ef
R10: 00007fc279fe7cb0 R11: 0000000000000246 R12: 00000000000871bf
R13: 00007fc279fe6270 R14: ffffffffffffffff R15: 00007ffdfcb84010
INFO: task syz.6.1583:12313 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.1583 state:D stack:25096 pid:12313 tgid:12308 ppid:8683 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121
fuse_direct_IO+0x712/0xf40 fs/fuse/file.c:2896
generic_file_direct_write+0x19a/0x410 mm/filemap.c:4248
fuse_cache_write_iter fs/fuse/file.c:1507 [inline]
fuse_file_write_iter+0x793/0x990 fs/fuse/file.c:1849
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x1f8/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc279d8f749
RSP: 002b:00007fc27ab73038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc279fe6180 RCX: 00007fc279d8f749
RDX: 0000000000000050 RSI: 0000200000000100 RDI: 0000000000000009
RBP: 00007fc279e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc279fe6218 R14: 00007fc279fe6180 R15: 00007ffdfcb83d98
Showing all locks held in the system:
1 lock held by rcu_tasks_trace/29:
#0: ffffffff8e3c8a70 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0x72d/0xe20 kernel/rcu/tasks.h:614
1 lock held by khungtaskd/31:
#0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/38:
#0: ffff88813ff69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc90000ae7c90 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff8e3d4c40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3816
6 locks held by kworker/1:2/932:
#0: ffff88801e29fd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc90003b77c90 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffff888143be9198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888143be9198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x52f0 drivers/usb/core/hub.c:5899
#3: ffff888143bec518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff888143bec518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff888143bec518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff888143bec518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff888143bec518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2b87/0x52f0 drivers/usb/core/hub.c:5953
#4: ffff888143ba4768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff888143ba4768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff888143ba4768 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff888143ba4768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2bb0/0x52f0 drivers/usb/core/hub.c:5953
#5: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
#5: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
3 locks held by kworker/u8:7/1318:
#0: ffff88813ff69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000441fc90 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff90136be8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303
2 locks held by getty/5574:
#0: ffff888036b050a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211
2 locks held by syz.6.1583/12313:
#0: ffff888043c4a420 (sb_writers#15){.+.+}-{0:0}, at: ksys_write+0x1f8/0x250 fs/read_write.c:738
#1: ffff8880472bab48 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff8880472bab48 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fuse_cache_write_iter fs/fuse/file.c:1494 [inline]
#1: ffff8880472bab48 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fuse_file_write_iter+0x2ee/0x990 fs/fuse/file.c:1849
1 lock held by syz.5.2107/14241:
#0: ffffffff8e3d4c40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3816
2 locks held by syz.4.2110/14252:
#0: ffffffff90136be8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff90136be8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3436
#1: ffffffff8e3d4d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311
=============================================
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 lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/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+0x133/0x180 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xe66/0x1180 kernel/hung_task.c:515
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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:rb_set_parent_color include/linux/rbtree_augmented.h:191 [inline]
RIP: 0010:__rb_insert lib/rbtree.c:100 [inline]
RIP: 0010:__rb_insert_augmented+0x58c/0x880 lib/rbtree.c:459
Code: 00 00 fc ff df 48 c1 e9 03 49 83 e4 fc 80 3c 11 00 4c 89 e3 0f 85 5d 01 00 00 4d 85 e4 4c 89 65 00 49 89 ec 0f 85 c1 fa ff ff <48> b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 80 3c 02 00 0f
RSP: 0018:ffffc90000a08d68 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff88803309ca10
RDX: 1ffff11006613942 RSI: ffff88807872b048 RDI: ffff88803309ca10
RBP: dffffc0000000000 R08: 1ffff1100f0e560a R09: ffff8880b853ac80
R10: ffff88803309ca40 R11: 0000000000000001 R12: ffff88803309ca10
R13: ffff88807872b000 R14: ffffffff818d20a0 R15: ffff88807872b048
FS: 0000000000000000(0000) GS:ffff888124a09000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34be7ff8 CR3: 0000000074012000 CR4: 00000000003526f0
Call Trace:
enqueue_entity kernel/sched/fair.c:5264 [inline]
enqueue_task_fair+0x41d/0x29e0 kernel/sched/fair.c:6932
enqueue_task+0xd4/0x550 kernel/sched/core.c:2094
activate_task kernel/sched/core.c:2135 [inline]
ttwu_do_activate+0x17d/0xab0 kernel/sched/core.c:3631
sched_ttwu_pending+0x2bc/0x640 kernel/sched/core.c:3730
csd_do_func kernel/smp.c:136 [inline]
__flush_smp_call_function_queue+0x4cf/0x8b0 kernel/smp.c:593
__sysvec_call_function_single+0x87/0x3b0 arch/x86/kernel/smp.c:271
instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
sysvec_call_function_single+0x9f/0xc0 arch/x86/kernel/smp.c:266
asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:704
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 06 60 02 c3 cc cc cc cc 0f 1f 00 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 13 59 13 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6
RAX: 000000000387f605 RBX: 0000000000000001 RCX: ffffffff8b7706d9
RDX: 0000000000000000 RSI: ffffffff8dac200a RDI: ffffffff8bf24280
RBP: ffffed1003b56498 R08: 0000000000000001 R09: ffffed10170a673d
R10: ffff8880b85339eb R11: ffff88801dab2ff0 R12: 0000000000000001
R13: ffff88801dab24c0 R14: ffffffff9087f7d0 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148