INFO: task syz.4.777:9960 blocked for more than 143 seconds. Not tainted 6.11.0-next-20240926-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.777 state:D stack:23904 pid:9960 tgid:9930 ppid:9377 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 io_schedule+0x8d/0x110 kernel/sched/core.c:7552 folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1310 folio_wait_writeback+0xe7/0x1e0 mm/page-writeback.c:3189 truncate_inode_pages_range+0xafd/0xfc0 mm/truncate.c:398 bchfs_fallocate+0x2d1/0x730 fs/bcachefs/fs-io.c:718 bch2_fallocate_dispatch+0x3ac/0x540 fs/bcachefs/fs-io.c:771 vfs_fallocate+0x623/0x7a0 fs/open.c:333 do_vfs_ioctl+0x2583/0x2e40 fs/ioctl.c:886 __do_sys_ioctl fs/ioctl.c:905 [inline] __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efc7777df39 RSP: 002b:00007efc784c0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007efc77936058 RCX: 00007efc7777df39 RDX: 0000000020000180 RSI: 0000000040305839 RDI: 0000000000000008 RBP: 00007efc777f0216 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007efc77936058 R15: 00007ffe17742ab8 Showing all locks held in the system: 2 locks held by kworker/u8:0/11: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffff8880b8628948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:989 1 lock held by khungtaskd/30: #0: ffffffff8e937f20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937f20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937f20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 4 locks held by kworker/u8:5/82: 2 locks held by dhcpcd/4898: #0: ffff88806cc136c8 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2404 #1: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6505 2 locks held by getty/4986: #0: ffff88814bf4d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:6/5277: #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90003ee7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003ee7d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u8:11/5665: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90009a57d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90009a57d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 2 locks held by syz-executor/9914: #0: ffff8880794340e0 (&type->s_umount_key#84){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880794340e0 (&type->s_umount_key#84){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880794340e0 (&type->s_umount_key#84){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffff888047200278 (&c->state_lock){+.+.}-{3:3}, at: __bch2_fs_stop+0xfd/0x540 fs/bcachefs/super.c:618 1 lock held by syz.4.777/9931: #0: ffff88805fe26420 (sb_writers#29){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2949 [inline] #0: ffff88805fe26420 (sb_writers#29){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 2 locks held by syz.4.777/9960: #0: ffff88805fe26420 (sb_writers#29){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2949 [inline] #0: ffff88805fe26420 (sb_writers#29){.+.+}-{0:0}, at: vfs_fallocate+0x59d/0x7a0 fs/open.c:332 #1: ffff8880580008c0 (&sb->s_type->i_mutex_key#35){++++}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline] #1: ffff8880580008c0 (&sb->s_type->i_mutex_key#35){++++}-{3:3}, at: bch2_fallocate_dispatch+0x1e2/0x540 fs/bcachefs/fs-io.c:762 2 locks held by bch-copygc/loop/9954: 1 lock held by syz-executor/10191: #0: ffffffff8e93d4b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93d4b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 3 locks held by bch-reclaim/loo/10328: 7 locks held by syz-executor/10775: #0: ffff88807d000420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2949 [inline] #0: ffff88807d000420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 #1: ffff888054241488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff888143f08e18 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f573228 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff88806a5170e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88806a5170e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88806a5170e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff88806a513250 (&devlink->lock_key#32){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1672 #6: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x71/0x5c0 drivers/net/netdevsim/netdev.c:773 1 lock held by syz-executor/10821: #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd5188 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 2 locks held by dhcpcd/11054: #0: ffff888077786808 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline] #0: ffff888077786808 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline] #0: ffff888077786808 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1427 #1: ffffffff8e93d4b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #1: ffffffff8e93d4b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-next-20240926-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10328 Comm: bch-reclaim/loo Not tainted 6.11.0-next-20240926-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:kasan_check_range+0x5/0x290 mm/kasan/generic.c:188 Code: 8e e8 bf dd e1 ff 90 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 <41> 57 41 56 41 54 53 b0 01 48 85 f6 0f 84 a0 01 00 00 4c 8d 04 37 RSP: 0018:ffffc900031ff6b0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff816f6c6d RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d24a8 RBP: ffffc900031ff830 R08: ffffffff942cd987 R09: 1ffffffff2859b30 R10: dffffc0000000000 R11: fffffbfff2859b31 R12: dffffc0000000000 R13: ffff88804724a578 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff355ad4f8 CR3: 0000000079596000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:570 [inline] cpu_online include/linux/cpumask.h:1117 [inline] trace_contention_begin+0x2d/0x120 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:610 [inline] __mutex_lock+0x147/0xd70 kernel/locking/mutex.c:752 __bch2_next_write_buffer_flush_journal_buf+0x60/0x2a0 fs/bcachefs/journal.c:870 bch2_next_write_buffer_flush_journal_buf+0xa3/0x1b0 fs/bcachefs/journal.c:904 fetch_wb_keys_from_journal fs/bcachefs/btree_write_buffer.c:486 [inline] btree_write_buffer_flush_seq+0x18c/0x1bc0 fs/bcachefs/btree_write_buffer.c:503 bch2_btree_write_buffer_journal_flush+0x4e/0x80 fs/bcachefs/btree_write_buffer.c:525 journal_flush_pins+0x5f7/0xb20 fs/bcachefs/journal_reclaim.c:565 __bch2_journal_reclaim+0x789/0xdc0 fs/bcachefs/journal_reclaim.c:698 bch2_journal_reclaim_thread+0x174/0x560 fs/bcachefs/journal_reclaim.c:740 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244