INFO: task syz-executor:5831 blocked for more than 144 seconds. Not tainted 6.15.0-syzkaller-10820-gcd2e103d57e5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21960 pid:5831 tgid:5831 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6781 __schedule_loop kernel/sched/core.c:6859 [inline] schedule+0x165/0x360 kernel/sched/core.c:6874 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2833 sync_filesystem+0x17a/0x230 fs/sync.c:64 generic_shutdown_super+0x6f/0x2c0 fs/super.c:622 kill_block_super+0x44/0x90 fs/super.c:1753 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f84b398fc97 RSP: 002b:00007ffd1f60ee88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f84b3a1089d RCX: 00007f84b398fc97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd1f60ef40 RBP: 00007ffd1f60ef40 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd1f60ffd0 R13: 00007f84b3a1089d R14: 000000000008e9b9 R15: 00007ffd1f610010 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13d080 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d080 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13d080 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:3/49: #0: ffff888143abc948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888143abc948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000ba7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000ba7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 3 locks held by kworker/u8:6/4115: #0: ffff88801a481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000c677bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000c677bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f50b248 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by getty/5581: #0: ffff88814c90b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5831: #0: ffff88803056c0e0 (&type->s_umount_key#89){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88803056c0e0 (&type->s_umount_key#89){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88803056c0e0 (&type->s_umount_key#89){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff8880248d47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880248d47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 7 locks held by segctord/13741: 2 locks held by syz.6.2711/15014: #0: ffffffff8f50b248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f50b248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f50b248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4054 #1: ffffffff8e142bb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #1: ffffffff8e142bb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 3 locks held by syz.1.2718/15037: #0: ffff8880536aee08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #0: ffff8880536aee08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff8880536aee08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391 #1: ffffffff8f56f830 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379 #2: ffff8880304f7cd8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nft_rcv_nl_event+0x116/0x640 net/netfilter/nf_tables_api.c:12093 2 locks held by syz.1.2718/15038: #0: ffff8880304f7cd8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3b/0x100 net/netfilter/nf_tables_api.c:11505 #1: ffffffff8e142bb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #1: ffffffff8e142bb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-10820-gcd2e103d57e5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 13741 Comm: segctord Not tainted 6.15.0-syzkaller-10820-gcd2e103d57e5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_preemption_disabled+0x3a/0x120 lib/smp_processor_id.c:55 Code: 37 07 48 89 44 24 08 65 8b 05 06 6e 37 07 65 8b 0d fb 6d 37 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d db 6d 37 07 48 3b 4c 24 08 <0f> 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9 ac 9e ab f5 cc RSP: 0018:ffffc90000a07a80 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffffff90bd4201 RCX: a1064aabc1eccc00 RDX: ffffc90000a07b01 RSI: ffffffff8be26f20 RDI: ffffffff8be26ee0 RBP: dffffc0000000000 R08: ffffc90000a08750 R09: ffffc90000a07bf8 R10: dffffc0000000000 R11: fffff52000140f81 R12: ffffc90000a08760 R13: ffffc90000a01000 R14: ffffc90000a07ba8 R15: ffffffff81727e15 FS: 0000000000000000(0000) GS:ffff888125d5f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30019ff8 CR3: 00000000753a3000 CR4: 0000000000350ef0 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:745 rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x1965/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4248 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:579 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] _sctp_make_chunk+0x5e/0x430 net/sctp/sm_make_chunk.c:1435 sctp_make_control net/sctp/sm_make_chunk.c:1482 [inline] sctp_make_heartbeat_ack+0x3b/0x310 net/sctp/sm_make_chunk.c:1193 sctp_sf_beat_8_3+0x4eb/0x7b0 net/sctp/sm_statefuns.c:1199 sctp_do_sm+0x1e7/0x5a20 net/sctp/sm_sideeffect.c:1166 sctp_assoc_bh_rcv+0x3f2/0x630 net/sctp/associola.c:1034 sctp_rcv+0x1ca6/0x2490 net/sctp/input.c:243 ip_protocol_deliver_rcu+0x2e0/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2fb/0x580 net/ipv4/ip_input.c:233 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317 __netif_receive_skb_one_core net/core/dev.c:5977 [inline] __netif_receive_skb+0x143/0x380 net/core/dev.c:6090 process_backlog+0x60e/0x14f0 net/core/dev.c:6442 __napi_poll+0xc7/0x480 net/core/dev.c:7414 napi_poll net/core/dev.c:7478 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7605 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:memcpy+0xe/0x20 arch/x86/lib/memcpy_64.S:39 Code: cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 48 89 f8 48 89 d1 f3 a4 f8 96 ab f5 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000b046dd8 EFLAGS: 00000202 RAX: ffffffff99ab68c0 RBX: 0000000000000017 RCX: 0000000000000000 RDX: 0000000000000017 RSI: ffffc9000b046e77 RDI: ffffffff99ab68d7 RBP: ffffc9000b046f10 R08: ffffffff99ab68d6 R09: 1ffffffff3356d1a R10: dffffc0000000000 R11: fffffbfff3356d1b R12: 000000000000006a R13: ffffffff99ab68c0 R14: 0000000000000000 R15: 000000000000006a record_print_text+0x26c/0x430 kernel/printk/printk.c:1489 printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:3024 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x4ca/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 __getblk_slow fs/buffer.c:1128 [inline] bdev_getblk+0x55d/0x690 fs/buffer.c:1467 __getblk include/linux/buffer_head.h:382 [inline] sb_getblk include/linux/buffer_head.h:388 [inline] nilfs_segbuf_extend_segsum+0x116/0x3b0 fs/nilfs2/segbuf.c:99 nilfs_segbuf_reset+0x37/0x140 fs/nilfs2/segbuf.c:135 nilfs_segctor_reset_segment_buffer fs/nilfs2/segment.c:423 [inline] nilfs_segctor_collect fs/nilfs2/segment.c:1543 [inline] nilfs_segctor_do_construct+0x1334/0x6a40 fs/nilfs2/segment.c:2122 nilfs_segctor_construct+0x17b/0x690 fs/nilfs2/segment.c:2462 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2570 [inline] nilfs_segctor_thread+0x6f7/0xe00 fs/nilfs2/segment.c:2684 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245