INFO: task syz.3.562:7996 blocked for more than 145 seconds. Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.562 state:D stack:25848 pid:7996 tgid:7993 ppid:5831 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 netfs_wait_for_request+0x1f0/0x600 fs/netfs/misc.c:450 netfs_unbuffered_write_iter_locked+0x52a/0x910 fs/netfs/direct_write.c:110 netfs_unbuffered_write_iter+0x4c4/0x660 fs/netfs/direct_write.c:193 do_iter_readv_writev+0x56e/0x7f0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_writev+0x14d/0x2d0 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6bc058e969 RSP: 002b:00007f6bc14e2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f6bc07b5fa0 RCX: 00007f6bc058e969 RDX: 0000000000000002 RSI: 0000200000000000 RDI: 0000000000000006 RBP: 00007f6bc0610ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6bc07b5fa0 R15: 00007ffef8f93d68 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:7/1110: 8 locks held by kworker/u8:8/1162: 2 locks held by getty/5596: #0: ffff88814bf290a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by syz.3.562/7996: #0: ffff88802f9c40f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 #1: ffff888141fa8428 (sb_writers#18){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3092 [inline] #1: ffff888141fa8428 (sb_writers#18){.+.+}-{0:0}, at: vfs_writev+0x288/0x960 fs/read_write.c:1055 #2: ffff8880582fa178 (&sb->s_type->i_mutex_key#26){++++}-{4:4}, at: netfs_start_io_direct+0x1ef/0x230 fs/netfs/locking.c:188 7 locks held by syz-executor/8950: #0: ffff88803547a428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3092 [inline] #0: ffff88803547a428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:682 #1: ffff88805490d888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffff8880276650f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8edab808 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:216 #4: ffff8880563fc0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff8880563fc0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff8880563fc0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1292 #5: ffff8880563f8250 (&devlink->lock_key#16){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8f50d908 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xdb/0x670 drivers/net/netdevsim/netdev.c:1063 4 locks held by syz.2.843/9048: #0: ffff888033728d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff888033728d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x1fe/0x500 net/bluetooth/hci_core.c:2678 #1: ffff888033728078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5213 #2: ffffffff8f675928 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2062 [inline] #2: ffffffff8f675928 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2543 #3: ffff888023eb9338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762 1 lock held by syz-executor/9132: #0: ffffffff8e144c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e144c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz.1.899/9243: #0: ffffffff8f50d908 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f50d908 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396 1 lock held by syz.4.902/9251: #0: ffffffff8f50d908 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f50d908 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #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:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 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: 9034 Comm: syz-executor Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x35/0xb0 kernel/rcu/tree.c:745 Code: 05 30 e8 f4 10 e8 db 89 bd 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 60 5c b9 8d 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 ec b1 7c 00 48 c7 c3 58 3f 9d 92 RSP: 0018:ffffc90003dff4c0 EFLAGS: 00000216 RAX: 1ffffffff1b72b8d RBX: 0000000000000001 RCX: c5911cd0e6a9d400 RDX: 0000000000000000 RSI: ffffffff8be27520 RDI: ffffffff8be274e0 RBP: ffffffff81ab766d R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff81acf820 R12: 0000000000000002 R13: ffffffff8e13f140 R14: ffffffff8db95c68 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125d5f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f517ace7d60 CR3: 000000000df38000 CR4: 0000000000350ef0 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5834 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] is_module_text_address+0x39/0x1e0 kernel/module/main.c:3731 kernel_text_address+0x94/0xe0 kernel/extable.c:119 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 vfree+0x25a/0x400 mm/vmalloc.c:3426 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6ad/0x22e0 kernel/exit.c:955 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 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:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa974b907fc Code: Unable to access opcode bytes at 0x7fa974b907d2. RSP: 002b:00007ffc738763f0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: 0000000000000058 RBX: 00007fa9758e4620 RCX: 00007fa974b907fc RDX: 0000000000000058 RSI: 00007fa9758e4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffc73876444 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fa9758e4670 R15: 0000000000000000