INFO: task kworker/u8:4:62 blocked for more than 143 seconds. Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:4 state:D stack:20184 pid:62 tgid:62 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108 write_inode fs/fs-writeback.c:1503 [inline] __writeback_single_inode+0x711/0x10d0 fs/fs-writeback.c:1723 writeback_sb_inodes+0x80c/0x1370 fs/fs-writeback.c:1954 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2025 wb_writeback+0x42f/0xbd0 fs/fs-writeback.c:2136 wb_check_background_flush fs/fs-writeback.c:2206 [inline] wb_do_writeback fs/fs-writeback.c:2294 [inline] wb_workfn+0xc58/0x1090 fs/fs-writeback.c:2321 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 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 3 locks held by kworker/1:1/51: #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: ffffc90000bb7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000bb7d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 4 locks held by kworker/u8:4/62: #0: ffff888020292948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff888020292948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900015d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900015d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff888030a500e8 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108 2 locks held by kworker/u8:5/76: 3 locks held by kworker/u8:6/1121: #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: ffffc900044f7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900044f7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 1 lock held by dhcpcd/4887: #0: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 2 locks held by getty/4980: #0: ffff888032e490a0 (&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 syz-executor/7058: 5 locks held by kworker/u8:9/7214: #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: ffffc90003fa7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003fa7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcb2cd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: cleanup_net+0x6af/0xcc0 net/core/net_namespace.c:616 #4: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 3 locks held by kworker/u8:10/7664: #0: ffff88814bb8e148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88814bb8e148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90004767d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90004767d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 2 locks held by syz.3.297/8082: #0: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888143be67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:388 [inline] #1: ffff888143be67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2797 2 locks held by syz.1.315/8266: #0: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888143be67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:388 [inline] #1: ffff888143be67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2797 2 locks held by syz-executor/8538: #0: ffff88805b17c0e0 (&type->s_umount_key#31){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805b17c0e0 (&type->s_umount_key#31){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88805b17c0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffffffff8e9f8fe8 (lock#3){+.+.}-{3:3}, at: __lru_add_drain_all+0x66/0x560 mm/swap.c:843 2 locks held by syz.2.341/8571: #0: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888143be67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:388 [inline] #1: ffff888143be67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2797 2 locks held by syz.1.380/8837: #0: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888143be67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:388 [inline] #1: ffff888143be67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2797 2 locks held by syz.2.409/9029: #0: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805fe7e0e0 (&type->s_umount_key#96){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888143be67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:388 [inline] #1: ffff888143be67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2797 2 locks held by syz-executor/9391: #0: ffffffff8fcb2cd0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcbf7c8 (rtnl_mutex){+.+.}-{3:3}, at: register_netdev+0x13/0x50 net/core/dev.c:10626 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #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: 7058 Comm: syz-executor Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:lookup_bh_lru fs/buffer.c:1373 [inline] RIP: 0010:__find_get_block+0x4eb/0x1150 fs/buffer.c:1400 Code: 3f 49 8d 5c 24 30 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 aa 97 db ff 48 8b 44 24 08 <48> 39 03 74 22 e8 4b 09 75 ff 49 83 fe f1 0f 85 60 ff ff ff eb 65 RSP: 0018:ffffc9000359f760 EFLAGS: 00000046 RAX: ffff888148c96780 RBX: ffff8880609b6b10 RCX: dffffc0000000000 RDX: ffff8880690dbc00 RSI: 0000000000000080 RDI: 0000000000000080 RBP: ffffc9000359f898 R08: ffffffff821fdc9d R09: 1ffffffff347bd7c R10: dffffc0000000000 R11: fffffbfff347bd7d R12: ffff8880609b6ae0 R13: 0000000000039940 R14: 0000000000000000 R15: 0000000000000080 FS: 000055555ead8500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3a99308178 CR3: 00000000278fc000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bdev_getblk+0x33/0x550 fs/buffer.c:1431 __bread_gfp+0x86/0x400 fs/buffer.c:1491 sb_bread include/linux/buffer_head.h:346 [inline] __exfat_ent_get fs/exfat/fatent.c:48 [inline] exfat_ent_get+0x14d/0x400 fs/exfat/fatent.c:97 __exfat_free_cluster+0x56f/0x990 fs/exfat/fatent.c:200 exfat_free_cluster+0x77/0xd0 fs/exfat/fatent.c:232 __exfat_truncate+0x745/0xa60 fs/exfat/file.c:235 exfat_evict_inode+0xd8/0x270 fs/exfat/inode.c:683 evict+0x4e8/0x9b0 fs/inode.c:723 do_unlinkat+0x512/0x830 fs/namei.c:4540 __do_sys_unlink fs/namei.c:4581 [inline] __se_sys_unlink fs/namei.c:4579 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4579 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: 0033:0x7f1e95d7d5a7 Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffeebc74df8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1e95d7d5a7 RDX: 00007ffeebc74e20 RSI: 00007ffeebc74eb0 RDI: 00007ffeebc74eb0 RBP: 00007ffeebc74eb0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffeebc75fa0 R13: 00007f1e95df0134 R14: 0000000000036283 R15: 00007ffeebc77060