INFO: task syz.4.135:6422 blocked for more than 143 seconds. Not tainted 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.135 state:D stack:25976 pid:6422 tgid:6390 ppid:5226 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x185a/0x4b70 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 io_schedule+0x8d/0x110 kernel/sched/core.c:7574 folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1309 folio_wait_writeback+0xe7/0x1e0 mm/page-writeback.c:3189 folio_prepare_writeback mm/page-writeback.c:2455 [inline] writeback_get_folio mm/page-writeback.c:2497 [inline] writeback_iter+0xb18/0x18d0 mm/page-writeback.c:2590 write_cache_pages+0xb1/0x230 mm/page-writeback.c:2639 bch2_writepages+0x14f/0x380 fs/bcachefs/fs-io-buffered.c:639 do_writepages+0x35d/0x870 mm/page-writeback.c:2683 filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:398 __filemap_fdatawrite_range mm/filemap.c:431 [inline] file_write_and_wait_range+0x195/0x280 mm/filemap.c:788 bch2_fsync+0x13a/0x360 fs/bcachefs/fs-io.c:199 generic_write_sync include/linux/fs.h:2871 [inline] bch2_write_iter+0x21d9/0x23f0 fs/bcachefs/fs-io-buffered.c:1055 new_sync_write fs/read_write.c:590 [inline] vfs_write+0xa6d/0xc90 fs/read_write.c:683 ksys_write+0x183/0x2b0 fs/read_write.c:736 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: 0033:0x7fa7d197dff9 RSP: 002b:00007fa7d13de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa7d1b36130 RCX: 00007fa7d197dff9 RDX: 00000000000001b1 RSI: 0000000020000500 RDI: 0000000000000004 RBP: 00007fa7d19f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fa7d1b36130 R15: 00007ffd45799e28 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 3 locks held by kworker/u8:4/62: 3 locks held by kworker/u8:7/2499: #0: ffff8881416b9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8881416b9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90008ec7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90008ec7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff88802f9680e0 (&type->s_umount_key#105){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 3 locks held by kworker/u8:10/2972: #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: ffffc90009e17d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90009e17d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 5 locks held by kworker/u8:11/3014: #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900098d7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900098d7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcb3e50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: cleanup_net+0x6af/0xcc0 net/core/net_namespace.c:616 #4: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 3 locks held by kworker/u8:12/3045: #0: ffff88802e983148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88802e983148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000a077d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000a077d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4736 2 locks held by dhcpcd/4892: #0: ffffffff8fca5468 (vlan_ioctl_mutex){+.+.}-{3:3}, at: sock_ioctl+0x661/0x8e0 net/socket.c:1308 #1: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: vlan_ioctl_handler+0x112/0x9d0 net/8021q/vlan.c:553 2 locks held by getty/4976: #0: ffff88802f2470a0 (&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/1:5/5279: #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: ffffc90004217d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90004217d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by syz.4.135/6391: #0: ffff88802f968420 (sb_writers#32){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x220 fs/splice.c:1163 2 locks held by syz.4.135/6422: #0: ffff88803171cef8 (&f->f_pos_lock){+.+.}-{3:3}, at: fdget_pos+0x24e/0x320 fs/file.c:1160 #1: ffff88802f968420 (sb_writers#32){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] #1: ffff88802f968420 (sb_writers#32){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 4 locks held by bch-reclaim/loo/6414: #0: ffff88805404b0a8 (&j->reclaim_lock){+.+.}-{3:3}, at: bch2_journal_reclaim_thread+0x167/0x560 fs/bcachefs/journal_reclaim.c:739 #1: ffff888054004398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:151 [inline] #1: ffff888054004398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:250 [inline] #1: ffff888054004398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7de/0xd20 fs/bcachefs/btree_iter.c:3215 #2: ffff888054004740 (&wb->flushing.lock){+.+.}-{3:3}, at: btree_write_buffer_flush_seq+0x1a39/0x1bc0 fs/bcachefs/btree_write_buffer.c:509 #3: ffff8880540266d0 (&c->gc_lock){++++}-{3:3}, at: bch2_btree_update_start+0x682/0x14e0 fs/bcachefs/btree_update_interior.c:1202 1 lock held by syz.4.192/6855: #0: ffff88802f9680e0 (&type->s_umount_key#105){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88802f9680e0 (&type->s_umount_key#105){++++}-{3:3}, at: super_lock+0x196/0x400 fs/super.c:120 1 lock held by syz.4.265/7475: #0: ffff88802f9680e0 (&type->s_umount_key#105){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88802f9680e0 (&type->s_umount_key#105){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 1 lock held by syz-executor/7535: #0: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 1 lock held by syz-executor/7579: #0: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 1 lock held by syz.4.284/7912: #0: ffff88802f9680e0 (&type->s_umount_key#105){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88802f9680e0 (&type->s_umount_key#105){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 1 lock held by syz.4.284/7936: #0: ffff88802f9680e0 (&type->s_umount_key#105){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88802f9680e0 (&type->s_umount_key#105){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 1 lock held by syz-executor/8411: #0: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcc0948 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6672 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 937 Comm: kworker/0:2 Not tainted 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events free_obj_work RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline] RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x6d5/0x22d0 arch/x86/kernel/unwind_orc.c:494 Code: 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 49 8d 1c 46 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 27 48 63 03 48 01 d8 48 8d 4b 04 4c 39 f8 4c 0f 46 f1 48 RSP: 0018:ffffc90003a67590 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffffffff90348580 RCX: dffffc0000000000 RDX: 00000000000b0001 RSI: ffffffff90adcc30 RDI: ffffffff814156e0 RBP: ffffffff90348598 R08: 000000000000000d R09: ffffc90003a67750 R10: ffffc90003a676b0 R11: ffffffff81809070 R12: ffffffff90348568 R13: ffffffff90348568 R14: ffffffff90348568 R15: ffffffff81fb3e8e FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f61990e000 CR3: 00000000469c8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kmem_cache_free+0x1a2/0x420 mm/slub.c:4681 free_obj_work+0x4ff/0x6d0 lib/debugobjects.c:331 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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