INFO: task kworker/u4:12:4746 blocked for more than 143 seconds. Not tainted 5.15.178-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:12 state:D stack:20120 pid: 4746 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165 f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:528 f2fs_write_inode+0x4be/0x660 fs/f2fs/inode.c:738 write_inode fs/fs-writeback.c:1495 [inline] __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1705 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:2001 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2106 wb_check_start_all fs/fs-writeback.c:2228 [inline] wb_do_writeback fs/fs-writeback.c:2254 [inline] wb_workfn+0x9f4/0x1130 fs/fs-writeback.c:2288 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task syz.8.518:6809 blocked for more than 144 seconds. Not tainted 5.15.178-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.518 state:D stack:26592 pid: 6809 ppid: 6513 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x293/0xab0 fs/fs-writeback.c:2770 iterate_supers+0x127/0x1e0 fs/super.c:718 ksys_sync+0xb9/0x1c0 fs/sync.c:102 __do_sys_sync+0xa/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f2dd1c29169 RSP: 002b:00007f2dcfa71038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f2dd1e42080 RCX: 00007f2dd1c29169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f2dd1e42080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2dd1e42080 R15: 00007ffe0dca4358 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8cb1fce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:1/144: #0: ffff8880175cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900010afd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8dc36b10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x166/0xc90 net/core/net_namespace.c:572 #3: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0xa4f/0xc40 net/core/dev.c:10664 1 lock held by dhcpcd/3840: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5644 2 locks held by getty/3932: #0: ffff88802d0e9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025c62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 3 locks held by kworker/1:5/4211: #0: ffff88802bd4f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000315fd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x1720 net/ipv6/addrconf.c:4113 3 locks held by kworker/u4:6/4224: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900031cfd20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 3 locks held by kworker/1:10/4470: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000325fd20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845 3 locks held by kworker/u4:9/4479: #0: ffff8880b8e3a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #1: ffffc9000337fd20 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff8880b8e28098 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:946 4 locks held by kworker/u4:12/4746: #0: ffff8881447d4938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000300fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff88807df480e0 (&type->s_umount_key#79){++++}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff8880633e51b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:528 5 locks held by syz.2.565/6761: 2 locks held by syz.8.518/6809: #0: ffff88807df480e0 (&type->s_umount_key#79){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:716 #1: ffff88802119c7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff88802119c7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768 2 locks held by syz.6.971/8662: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3440 #1: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845 1 lock held by syz.5.975/8682: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3440 1 lock held by syz.1.979/8694: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3440 2 locks held by syz.1.979/8697: #0: ffffffff8d4d72e8 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x10e/0x1cd0 drivers/net/ppp/ppp_generic.c:726 #1: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: ppp_create_interface drivers/net/ppp/ppp_generic.c:3345 [inline] #1: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1057 [inline] #1: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x6f4/0x1cd0 drivers/net/ppp/ppp_generic.c:730 1 lock held by syz.1.979/8699: #0: ffffffff8d4d72e8 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x10e/0x1cd0 drivers/net/ppp/ppp_generic.c:726 1 lock held by syz.9.982/8706: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x460/0x2270 drivers/net/tun.c:3052 1 lock held by syz.9.982/8709: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x460/0x2270 drivers/net/tun.c:3052 1 lock held by syz.9.982/8712: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: tun_set_queue drivers/net/tun.c:2923 [inline] #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3f2/0x2270 drivers/net/tun.c:3045 1 lock held by syz.7.981/8708: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5644 1 lock held by syz.7.981/8711: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5644 1 lock held by syz.7.981/8714: #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8dc42788 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5644 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6761 Comm: syz.2.565 Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:mark_lock+0x7/0x340 kernel/locking/lockdep.c:4552 Code: e1 07 80 c1 03 38 c1 0f 8c 73 ff ff ff 4c 89 ff e8 ae 30 67 00 e9 66 ff ff ff e8 14 12 dc 08 0f 1f 40 00 55 41 57 41 56 41 55 <41> 54 53 48 83 ec 10 49 89 f7 48 89 3c 24 49 bd 00 00 00 00 00 fc RSP: 0018:ffffc900030ee938 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff888026d68ad0 RCX: dffffc0000000000 RDX: 0000000000000006 RSI: ffff888026d68bb8 RDI: ffff888026d68000 RBP: ffff888026d68000 R08: dffffc0000000000 R09: fffffbfff213184a R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000005 R13: ffff888026d68ae8 R14: 0000000000000005 R15: ffff888026d68bd8 FS: 00007fa8e2d546c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055624f718680 CR3: 000000001f944000 CR4: 00000000003506e0 Call Trace: __lock_acquire+0xc78/0x1ff0 kernel/locking/lockdep.c:4966 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:363 [inline] __lookup_nat_cache+0x7c/0x290 fs/f2fs/node.c:214 f2fs_get_node_info+0xfa/0x12c0 fs/f2fs/node.c:564 is_alive fs/f2fs/gc.c:1015 [inline] gc_data_segment fs/f2fs/gc.c:1466 [inline] do_garbage_collect+0x22cd/0x7540 fs/f2fs/gc.c:1671 f2fs_gc+0x9d2/0x1c30 fs/f2fs/gc.c:1765 f2fs_balance_fs+0x4e8/0x6a0 fs/f2fs/segment.c:529 f2fs_map_blocks+0x265b/0x3720 fs/f2fs/data.c:1700 expand_inode_data+0x5dd/0xa40 fs/f2fs/file.c:1709 f2fs_fallocate+0x42d/0x910 fs/f2fs/file.c:1805 vfs_fallocate+0x54a/0x6b0 fs/open.c:308 do_vfs_ioctl+0x2317/0x2b70 fs/ioctl.c:853 __do_sys_ioctl fs/ioctl.c:872 [inline] __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa8e4f0c169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fa8e2d54038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa8e5125080 RCX: 00007fa8e4f0c169 RDX: 00004000000000c0 RSI: 0000000040305828 RDI: 0000000000000005 RBP: 00007fa8e4f8d2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa8e5125080 R15: 00007fff2e218cf8