INFO: task syz-executor:4190 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21824 pid: 4190 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 gfs2_gl_hash_clear+0x1a4/0x2f0 fs/gfs2/glock.c:2183 gfs2_put_super+0x769/0x7d0 fs/gfs2/super.c:624 generic_shutdown_super+0x130/0x300 fs/super.c:475 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fd3ea2eba77 RSP: 002b:00007ffe61972248 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fd3ea36ed7d RCX: 00007fd3ea2eba77 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe61972300 RBP: 00007ffe61972300 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe61973390 R13: 00007fd3ea36ed7d R14: 00000000000157d2 R15: 00007ffe619733d0 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by udevd/3560: #0: ffff88801fff3d18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 #1: ffff88814759a468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x6a/0x100 drivers/block/loop.c:2056 2 locks held by getty/3945: #0: ffff88802be85098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/4190: #0: ffff88805231c0e0 (&type->s_umount_key#87){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 2 locks held by kworker/1:6/4243: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003e9fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 1 lock held by udevd/4330: #0: ffff88801fff3d18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 3 locks held by kworker/0:11/4511: #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:483 #1: ffff8880b9027888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4d6/0x810 kernel/sched/psi.c:891 #2: ffff888023a7b530 (&idev->mc_lock){+.+.}-{3:3}, at: mld_ifc_work+0x29/0xb40 net/ipv6/mcast.c:2657 3 locks held by kworker/u4:12/4620: #0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90002fefd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c1210b0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043 3 locks held by kworker/u4:15/4692: 3 locks held by kworker/1:12/4932: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900035afd00 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c1210b0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043 3 locks held by kworker/0:18/5010: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000303fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff8880775f5240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480 1 lock held by syz.5.234/5953: #0: ffff88805231c0e0 (&type->s_umount_key#87){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz-executor/7232: #0: ffffffff8c1211a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8c1211a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 1 lock held by syz.3.432/7343: #0: ffff88805231c0e0 ( &type->s_umount_key#87){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.1.439/7405: #0: ffff88805231c0e0 (&type->s_umount_key#87){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.1.439/7406: #0: ffff88805231c0e0 (&type->s_umount_key#87){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.0.504/7912: #0: ffff88805231c0e0 (&type->s_umount_key#87){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 5 locks held by syz-executor/8384: 1 lock held by syz.8.600/8648: #0: ffff88814759a468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 1 lock held by dhcpcd-run-hook/8706: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 146 Comm: kworker/u5:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: btrfs-worker-high btrfs_work_helper RIP: 0010:preempt_count_add+0x5d/0x190 kernel/sched/core.c:5512 Code: f1 fe b0 7e 65 01 3d ea fe b0 7e 48 c7 c0 80 0f 0b 96 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 e6 00 00 00 83 3d 83 9e b9 14 00 <75> 11 65 8b 05 c2 fe b0 7e 0f b6 c0 3d f5 00 00 00 73 58 65 8b 05 RSP: 0018:ffffc90000007b40 EFLAGS: 00000246 RAX: 0000000000000004 RBX: ffff88806081a060 RCX: ffffffff960b0f03 RDX: 0000000000000100 RSI: ffffffff8a59e7e0 RDI: 0000000000000001 RBP: ffffc90000007c90 R08: dffffc0000000000 R09: fffffbfff1ad26b6 R10: fffffbfff1ad26b6 R11: 1ffffffff1ad26b5 R12: ffff88806081a010 R13: ffffffff87eb8180 R14: ffff88806081a060 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d453280660 CR3: 000000004a88f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock include/linux/spinlock_api_smp.h:141 [inline] _raw_spin_lock+0xe/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:364 [inline] garp_join_timer+0x21/0x120 net/802/garp.c:418 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:console_trylock_spinning+0x2cd/0x350 kernel/printk/printk.c:1909 Code: 85 db 74 9d e8 64 a2 18 00 fb 31 c0 eb 48 e8 5a a2 18 00 e8 95 bd 42 08 48 85 db 74 d1 e8 4b a2 18 00 fb 48 c7 c7 60 12 11 8c <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 68 c6 29 5f RSP: 0018:ffffc9000172f360 EFLAGS: 00000293 RAX: ffffffff815f29c5 RBX: 0000000000000200 RCX: ffff88801ccc8000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8c111260 RBP: ffffc9000172f430 R08: dffffc0000000000 R09: fffffbfff1ff5446 R10: fffffbfff1ff5446 R11: 1ffffffff1ff5445 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff920002e5e6c vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273 _printk+0xcc/0x110 kernel/printk/printk.c:2299 handle_bad_sector block/blk-core.c:655 [inline] bio_check_eod block/blk-core.c:728 [inline] submit_bio_checks+0x107e/0x18f0 block/blk-core.c:812 __submit_bio+0x59e/0x810 block/blk-core.c:911 __submit_bio_noacct_mq block/blk-core.c:997 [inline] submit_bio_noacct+0x5f1/0x6d0 block/blk-core.c:1027 submit_bio+0x2be/0x560 block/blk-core.c:1089 submit_stripe_bio fs/btrfs/volumes.c:6831 [inline] btrfs_map_bio+0xc7f/0x1310 fs/btrfs/volumes.c:6920 run_one_async_done+0x10f/0x1f0 fs/btrfs/disk-io.c:767 run_ordered_work fs/btrfs/async-thread.c:255 [inline] btrfs_work_helper+0x524/0xb80 fs/btrfs/async-thread.c:335 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287