INFO: task syz.3.130:6912 blocked for more than 143 seconds. Not tainted 6.15.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.130 state:D stack:25256 pid:6912 tgid:6910 ppid:5825 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 percpu_rwsem_wait+0x2ab/0x300 kernel/locking/percpu-rwsem.c:162 __percpu_down_read+0xe3/0x120 kernel/locking/percpu-rwsem.c:177 percpu_down_read include/linux/percpu-rwsem.h:66 [inline] __sb_start_write include/linux/fs.h:1783 [inline] sb_start_write+0x185/0x1c0 include/linux/fs.h:1919 mnt_want_write+0x41/0x90 fs/namespace.c:556 filename_create+0x13a/0x470 fs/namei.c:4125 do_mkdirat+0xa0/0x590 fs/namei.c:4384 __do_sys_mkdir fs/namei.c:4414 [inline] __se_sys_mkdir fs/namei.c:4412 [inline] __x64_sys_mkdir+0x6c/0x80 fs/namei.c:4412 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb0f0f8e969 RSP: 002b:00007fb0f1d22038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007fb0f11b5fa0 RCX: 00007fb0f0f8e969 RDX: 0000000000000000 RSI: 0000000000000092 RDI: 00002000000004c0 RBP: 00007fb0f1010ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb0f11b5fa0 R15: 00007ffc9daf5e78 INFO: task syz.3.130:6915 blocked for more than 144 seconds. Not tainted 6.15.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.130 state:D stack:26376 pid:6915 tgid:6910 ppid:5825 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 percpu_rwsem_wait+0x2ab/0x300 kernel/locking/percpu-rwsem.c:162 __percpu_down_read+0xe3/0x120 kernel/locking/percpu-rwsem.c:177 percpu_down_read include/linux/percpu-rwsem.h:66 [inline] __sb_start_write include/linux/fs.h:1783 [inline] sb_start_write+0x185/0x1c0 include/linux/fs.h:1919 mnt_want_write+0x41/0x90 fs/namespace.c:556 open_last_lookups fs/namei.c:3789 [inline] path_openat+0x85d/0x3830 fs/namei.c:4036 do_filp_open+0x1fa/0x410 fs/namei.c:4066 do_sys_openat2+0x121/0x1c0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_open fs/open.c:1452 [inline] __se_sys_open fs/open.c:1448 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1448 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb0f0f8e969 RSP: 002b:00007fb0eedf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fb0f11b6080 RCX: 00007fb0f0f8e969 RDX: 0000000000000000 RSI: 0000000000109042 RDI: 0000200000000380 RBP: 00007fb0f1010ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb0f11b6080 R15: 00007ffc9daf5e78 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: 3 locks held by kworker/u8:0/12: #0: ffff88814ce17148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88814ce17148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000117c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000117c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4195 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 1 lock held by kworker/1:1/47: 2 locks held by kworker/u8:3/53: #0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffffc90000be7c60 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000be7c60 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 3 locks held by kworker/u8:4/63: #0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8923b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 #2: ffff8880b8925558 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1046 [inline] #2: ffff8880b8925558 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1127 1 lock held by dhcpcd/5489: #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x20f/0x330 net/ipv6/addrconf.c:4800 2 locks held by getty/5583: #0: ffff8880306750a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz.3.130/6912: #0: ffff8880339e2420 (sb_writers#14){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 1 lock held by syz.3.130/6915: #0: ffff8880339e2420 (sb_writers#14){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 1 lock held by syz-executor/8406: #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 3 locks held by syz-executor/9097: #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064 #1: ffff88805ea194e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x227/0x420 drivers/net/wireguard/device.c:50 #2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz-executor/9329: #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5028 4 locks held by syz.0.373/9709: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 8406 Comm: syz-executor Not tainted 6.15.0-rc4-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:__asan_memset+0x0/0x50 mm/kasan/shadow.c:83 Code: 48 8b 0c 24 ba 01 00 00 00 e9 1c e6 ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 56 53 48 89 d3 89 f5 49 89 fe 48 8b 4c 24 18 48 RSP: 0018:ffffc90000a08650 EFLAGS: 00000046 RAX: 1ffff920001410ec RBX: ffffc90000a08760 RCX: 1ffff92000141001 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90000a08778 RBP: dffffc0000000000 R08: 000000000000000c R09: 0000000000080000 R10: 0000000000000000 R11: ffffffff817199f5 R12: ffffc90000a08870 R13: ffffc90000a08778 R14: ffffc90000a08728 R15: ffffc90000a08770 FS: 00005555870ae500(0000) GS:ffff888126202000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9ed9fff000 CR3: 0000000024438000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xc98/0x2390 arch/x86/kernel/unwind_orc.c:592 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:548 insert_work+0x3d/0x330 kernel/workqueue.c:2183 __queue_work+0xcfc/0xfe0 kernel/workqueue.c:2341 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1789 expire_timers kernel/time/timer.c:1835 [inline] __run_timers kernel/time/timer.c:2414 [inline] __run_timer_base+0x646/0x860 kernel/time/timer.c:2426 run_timer_base kernel/time/timer.c:2435 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2445 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline] RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449 Code: 85 32 01 00 00 e8 31 f3 1e 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 20 f3 1e 00 eb 06 e8 19 f3 1e 00 fb 48 c7 c7 80 fa f2 8d <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 f9 3f RSP: 0018:ffffc9000401f940 EFLAGS: 00000293 RAX: ffffffff81a0cac7 RBX: ffffffff81a0c984 RCX: ffff8880311a0000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df2fa80 RBP: ffffc9000401fa50 R08: ffffffff8f7d9f77 R09: 1ffffffff1efb3ee R10: dffffc0000000000 R11: fffffbfff1efb3ef R12: dffffc0000000000 R13: 1ffff92000803f2c R14: 0000000000000200 R15: 000000000000005a _printk+0xcf/0x120 kernel/printk/printk.c:2475 _btrfs_printk+0x562/0x5b0 fs/btrfs/messages.c:248 btrfs_put_super+0x69/0x80 fs/btrfs/super.c:73 generic_shutdown_super+0x132/0x2c0 fs/super.c:642 kill_anon_super+0x3b/0x70 fs/super.c:1237 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2099 deactivate_locked_super+0xb9/0x130 fs/super.c:473 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1435 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7eff0798fc97 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd8239d358 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007eff07a1089d RCX: 00007eff0798fc97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd8239d410 RBP: 00007ffd8239d410 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd8239e4a0 R13: 00007eff07a1089d R14: 000000000004b408 R15: 00007ffd8239e4e0