INFO: task syz.4.177:7756 blocked for more than 143 seconds. Not tainted 6.15.0-rc3-syzkaller-00001-g9d7a0577c9db #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.177 state:D stack:27944 pid:7756 tgid:7734 ppid:6930 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_write_slowpath+0xedd/0x1420 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write_nested+0x1e2/0x220 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:902 [inline] do_rmdir+0x265/0x5c0 fs/namei.c:4501 __do_sys_rmdir fs/namei.c:4528 [inline] __se_sys_rmdir fs/namei.c:4526 [inline] __x64_sys_rmdir+0x47/0x50 fs/namei.c:4526 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8a9458e169 RSP: 002b:00007f8a954c2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007f8a947b6080 RCX: 00007f8a9458e169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000100 RBP: 00007f8a94610a68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f8a947b6080 R15: 00007ffcf2b4e198 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: #0: ffff88801bef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801bef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000117c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000117c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900de7d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17c/0xd60 net/core/net_namespace.c:608 #3: ffffffff900eb308 (rtnl_mutex){+.+.}-{4:4}, at: fib_net_exit_batch+0x22/0xf0 net/ipv4/fib_frontend.c:1675 1 lock held by khungtaskd/31: #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 3 locks held by kworker/u8:4/63: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90001557c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90001557c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900eb308 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by dhcpcd/5496: #0: ffffffff900cfd88 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x6d1/0x900 net/socket.c:1273 #1: ffffffff900eb308 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0x118/0xa20 net/8021q/vlan.c:554 2 locks held by getty/5590: #0: ffff888030ea60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000334b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:3/5880: #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc900048bfc60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900048bfc60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #2: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x384/0x830 kernel/rcu/tree_exp.h:998 5 locks held by syz.4.177/7735: #0: ffff8880639ec420 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:556 #1: ffff888056c145a0 (&sb->s_type->i_mutex_key#30/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff888056c145a0 (&sb->s_type->i_mutex_key#30/1){+.+.}-{4:4}, at: filename_create+0x262/0x510 fs/namei.c:4132 #2: ffff888056c14988 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x359/0xf40 fs/bcachefs/fs.c:550 #3: ffff88803ba84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff88803ba84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff88803ba84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7ed/0xd40 fs/bcachefs/btree_iter.c:3382 #4: ffff88803baa6590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68a/0x16c0 fs/bcachefs/btree_update_interior.c:1179 2 locks held by syz.4.177/7756: #0: ffff8880639ec420 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:556 #1: ffff888056c145a0 (&sb->s_type->i_mutex_key#30/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff888056c145a0 (&sb->s_type->i_mutex_key#30/1){+.+.}-{4:4}, at: do_rmdir+0x265/0x5c0 fs/namei.c:4501 2 locks held by bch-copygc/loop/7754: 1 lock held by syz-executor/9553: #0: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x454/0x830 kernel/rcu/tree_exp.h:998 2 locks held by syz-executor/9668: #0: ffffffff900de7d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:514 #1: ffffffff900eb308 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2a7/0x810 net/ipv4/ip_tunnel.c:1160 2 locks held by syz-executor/9672: #0: ffffffff900de7d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:514 #1: ffffffff900eb308 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2a7/0x810 net/ipv4/ip_tunnel.c:1160 4 locks held by syz.5.361/9678: #0: ffff88807f9b4d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff88807f9b4d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2678 #1: ffff88807f9b4078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x60f/0x1260 net/bluetooth/hci_sync.c:5213 #2: ffffffff90251468 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2066 [inline] #2: ffffffff90251468 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2701 #3: ffff888075ff0b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x71/0x690 net/bluetooth/l2cap_core.c:1761 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00001-g9d7a0577c9db #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 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+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b7/0x940 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: 3007 Comm: kworker/u8:8 Not tainted 6.15.0-rc3-syzkaller-00001-g9d7a0577c9db #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_wait_context kernel/locking/lockdep.c:4902 [inline] RIP: 0010:__lock_acquire+0x5a5/0xd80 kernel/locking/lockdep.c:5185 Code: ff ff 89 d0 e9 44 ff ff ff 48 c7 c7 f0 ef c0 8e 48 89 de 44 89 c5 e8 4a 95 99 03 41 89 e8 e9 51 ff ff ff 44 89 f0 38 44 24 34 <4c> 8b 64 24 38 4c 8b 74 24 20 76 1c 44 89 c5 e8 47 30 5a 03 41 89 RSP: 0018:ffffc9000ba47998 EFLAGS: 00000097 RAX: 00000000303be505 RBX: 0000000000000002 RCX: 0000000000000002 RDX: 0000000000000003 RSI: ffff8880303be4f0 RDI: 0000000000000000 RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880303be560 R13: ffff8880303bda00 R14: 00000000303be505 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b26fc39ff8 CR3: 000000003514e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 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