INFO: task syz.5.867:8841 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.867 state:D stack:25768 pid:8841 tgid:8841 ppid:5858 task_flags:0x40044c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2834 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:1766 ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7395 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa9dd9c1465 RSP: 002b:00007fa9de780f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007fa9ddbd6090 RCX: 00007fa9dd9c1465 RDX: 00007fa9de780fc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fa9dda11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007fa9ddbd6128 R14: 00007fa9ddbd6090 R15: 00007ffd983da3e8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5620: #0: ffff8880339660a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 7 locks held by kworker/u8:13/6095: 4 locks held by kworker/u8:27/6109: 2 locks held by syz.5.867/8841: #0: ffff88802eb780e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88802eb780e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88802eb780e0 (&type->s_umount_key#31){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff888142f447d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888142f447d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2832 4 locks held by syz.0.1227/10055: 2 locks held by syz-executor/10928: #0: ffffffff8eca94a0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8eca94a0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8eca94a0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f539e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f539e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f539e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 2 locks held by syz-executor/10984: #0: ffffffff8f52cfd0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:566 #1: ffffffff8f539e88 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160 6 locks held by syz.8.1484/10993: #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644 #1: ffff8880b8724008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffffffff8de16888 (mount_lock.seqcount){+.+.}-{0:0}, at: free_nsproxy+0x3e/0x350 kernel/nsproxy.c:188 #3: ffff88807e2bda68 (&new_ns->poll){....}-{3:3}, at: __wake_up_common_lock+0x2f/0x1f0 kernel/sched/wait.c:124 #4: ffff8880b8739718 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x809/0xfb0 kernel/workqueue.c:-1 #5: ffff8880303f2828 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline] #5: ffff8880303f2828 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x67/0x12b0 kernel/sched/core.c:4216 1 lock held by syz.4.1486/11003: #0: ffffffff8f539e88 (rtnl_mutex){+.+.}-{4:4}, at: do_ip_setsockopt+0xeee/0x2d00 net/ipv4/ip_sockglue.c:1077 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6109 Comm: kworker/u8:27 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: writeback wb_workfn (flush-7:5) RIP: 0010:match_held_lock+0x7b/0xc0 kernel/locking/lockdep.c:5337 Code: c7 c2 10 73 49 93 48 29 d0 48 c1 f8 03 48 ba 29 5c 8f c2 f5 28 5c 8f 48 0f af d0 bb 01 00 00 00 48 39 ca 74 02 31 db 89 d8 5b <41> 5e e9 79 f2 95 f5 cc 90 e8 b7 d7 4a f9 85 c0 74 22 83 3d c0 87 RSP: 0018:ffffc900000071e8 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff88802c190b90 RCX: 6a4a720bb73ea100 RDX: ffff88802c190000 RSI: ffffffff8e13a0e0 RDI: ffff88802c190b90 RBP: 00000000ffffffff R08: ffff88802d008667 R09: 1ffff11005a010cc R10: dffffc0000000000 R11: ffffed1005a010cd R12: 0000000000000046 R13: ffff88802c190000 R14: ffffffff8e13a0e0 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff888125c15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000404030 CR3: 0000000027368000 CR4: 0000000000350ef0 Call Trace: __lock_is_held kernel/locking/lockdep.c:5601 [inline] lock_is_held_type+0xa8/0x190 kernel/locking/lockdep.c:5940 lock_is_held include/linux/lockdep.h:249 [inline] rcu_read_lock_any_held+0x89/0x120 kernel/rcu/update.c:386 get_work_pool+0x55/0x180 kernel/workqueue.c:888 __queue_work+0x605/0xfb0 kernel/workqueue.c:2281 queue_work_on+0x181/0x270 kernel/workqueue.c:2390 __ieee80211_queue_skb_to_iface+0xf1/0x280 net/mac80211/rx.c:233 ieee80211_queue_skb_to_iface net/mac80211/rx.c:255 [inline] ieee80211_rx_h_mgmt+0x493/0x650 net/mac80211/rx.c:4066 ieee80211_rx_handlers+0x668c/0xb760 net/mac80211/rx.c:4141 ieee80211_invoke_rx_handlers net/mac80211/rx.c:4171 [inline] ieee80211_prepare_and_rx_handle+0x266f/0x63f0 net/mac80211/rx.c:5031 __ieee80211_rx_handle_packet net/mac80211/rx.c:5288 [inline] ieee80211_rx_list+0x21b8/0x2a90 net/mac80211/rx.c:5423 ieee80211_rx_napi+0x1a8/0x3d0 net/mac80211/rx.c:5446 ieee80211_rx include/net/mac80211.h:5210 [inline] ieee80211_handle_queued_frames+0xe8/0x1f0 net/mac80211/main.c:453 tasklet_action_common+0x36c/0x580 kernel/softirq.c:829 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:console_trylock_spinning kernel/printk/printk.c:2061 [inline] RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449 Code: 85 32 01 00 00 e8 c1 87 1f 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 b0 87 1f 00 eb 06 e8 a9 87 1f 00 fb 48 c7 c7 80 e3 12 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 b9 35 RSP: 0018:ffffc9000b30e1e0 EFLAGS: 00000293 RAX: ffffffff81a03757 RBX: ffffffff81a03614 RCX: ffff88802c190000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e12e380 RBP: ffffc9000b30e2f0 R08: ffffffff8fa3a537 R09: 1ffffffff1f474a6 R10: dffffc0000000000 R11: fffffbfff1f474a7 R12: dffffc0000000000 R13: 1ffff92001661c40 R14: 0000000000000200 R15: 0000000000000069 _printk+0xcf/0x120 kernel/printk/printk.c:2475 __ext4_error_inode+0x46b/0x4f0 fs/ext4/super.c:844 __ext4_mark_inode_dirty+0x18c/0x700 fs/ext4/inode.c:6512 ext4_split_extent_at+0x5e4/0xf70 fs/ext4/extents.c:3329 ext4_split_extent+0x1af/0x6e0 fs/ext4/extents.c:3377 ext4_split_convert_extents fs/ext4/extents.c:3743 [inline] ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3915 [inline] ext4_ext_map_blocks+0x1db2/0x6ac0 fs/ext4/extents.c:4274 ext4_map_create_blocks fs/ext4/inode.c:609 [inline] ext4_map_blocks+0x860/0x1740 fs/ext4/inode.c:811 mpage_map_one_extent fs/ext4/inode.c:2374 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2468 [inline] ext4_do_writepages+0x1f88/0x4610 fs/ext4/inode.c:2931 ext4_writepages+0x205/0x350 fs/ext4/inode.c:3025 do_writepages+0x32e/0x550 mm/page-writeback.c:2634 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:1976 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x409/0xef0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245