INFO: task syz.5.604:8273 blocked for more than 144 seconds. Not tainted 6.15.0-rc7-syzkaller-00007-g4a95bc121ccd #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.604 state:D stack:26136 pid:8273 tgid:8272 ppid:6820 task_flags:0x400140 flags:0x00004004 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 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526 __super_lock fs/super.c:58 [inline] super_lock+0x2a9/0x3b0 fs/super.c:120 super_lock_shared fs/super.c:139 [inline] iterate_supers+0x80/0x180 fs/super.c:931 ksys_sync+0x94/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7f22eab8e969 RSP: 002b:00007f22eb9d0038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f22eadb5fa0 RCX: 00007f22eab8e969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f22eadb5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f22eadb5fa0 R15: 00007ffda6b586b8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 3 locks held by kworker/u8:4/78: #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc900015b7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900015b7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e8588 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by getty/5583: #0: ffff8880303060a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/u9:5/5829: #0: ffff888023cb3148 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888023cb3148 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000466fc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000466fc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffff88805fe88d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0 net/bluetooth/hci_sync.c:331 1 lock held by syz-executor/5830: #0: ffff888021b3c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888021b3c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888021b3c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 1 lock held by syz.5.604/8273: #0: ffff888021b3c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888021b3c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 1 lock held by syz.6.1044/9743: #0: ffff888021b3c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888021b3c0e0 (&type->s_umount_key#54){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 3 locks held by syz-executor/9894: #0: ffffffff8ea81fe0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ea81fe0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ea81fe0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f2e8588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2e8588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f2e8588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064 #2: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #2: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 4 locks held by syz.7.1103/9965: 1 lock held by syz.0.1107/9968: #0: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 2 locks held by syz.4.1108/9974: #0: ffffffff8f34cb70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f2e8588 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:16693 1 lock held by syz.4.1108/9975: #0: ffffffff8f2e8588 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1d90 drivers/net/tun.c:3038 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00007-g4a95bc121ccd #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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+0x711/0x8a0 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: 0 Comm: swapper/1 Not tainted 6.15.0-rc7-syzkaller-00007-g4a95bc121ccd #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 Code: 43 d4 02 00 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 a3 9f 18 00 f3 0f 1e fa fb f4 18 d4 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: eabebb747aaa0600 RBX: ffffffff81977028 RCX: eabebb747aaa0600 RDX: 0000000000000001 RSI: ffffffff8d73ac7a RDI: ffffffff8bc120c0 RBP: ffffc90000197f20 R08: ffff8880b8932b5b R09: 1ffff1101712656b R10: dffffc0000000000 R11: ffffed101712656c R12: ffffffff8f7e0970 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110038d8b40 FS: 0000000000000000(0000) GS:ffff8881261f6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563f3f00b000 CR3: 000000007e52c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147