INFO: task syz.8.4828:31588 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.4828 state:D stack:27560 pid:31588 tgid:31575 ppid:25796 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7379 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821 sync_bdevs+0x276/0x470 block/bdev.c:1297 ksys_sync fs/sync.c:105 [inline] __ia32_sys_sync+0xc5/0x120 fs/sync.c:111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f54e399ce59 RSP: 002b:00007f54e48ef028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f54e3c16090 RCX: 00007f54e399ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f54e3c16090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f54e3c16128 R14: 00007f54e3c16090 R15: 00007ffe9dade668 INFO: lockdep is turned off. NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 1823 Comm: syz.0.5359 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:dummy_timer+0x53b/0x4b40 drivers/usb/gadget/udc/dummy_hcd.c:1845 Code: 80 a6 00 0b 00 00 fb 49 8d be 78 0b 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 68 45 00 00 41 80 a6 78 0b 00 00 fb <49> 8d be f0 0b 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f RSP: 0018:ffffc90000007b40 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88802ba7d410 RCX: 1ffff1100574fa94 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888028914b78 RBP: ffffc90000007e10 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f54 R12: ffff88802ba7d488 R13: dffffc0000000000 R14: ffff888028914000 R15: ffff88802ba7d400 FS: 00007f25caa996c0(0000) GS:ffff88812525a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3f9a00a000 CR3: 0000000079911000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2096 hrtimer_run_softirq+0x17a/0x240 kernel/time/hrtimer.c:2113 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478 Code: 0f 84 44 ff ff ff e8 22 6f 21 00 fb eb 44 e8 1a 6f 21 00 e8 c5 6f 08 0a 4d 85 f6 74 94 e8 0b 6f 21 00 fb 48 c7 c7 e0 be 94 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 ab 1c RSP: 0018:ffffc90003907840 EFLAGS: 00000246 RAX: ffffffff81a4c565 RBX: ffffffff81a4c3df RCX: 0000000000080000 RDX: ffffc90010539000 RSI: 000000000007ffff RDI: ffffffff8e94bee0 RBP: ffffc900039078f0 R08: ffffffff903189f7 R09: 1ffffffff206313e R10: dffffc0000000000 R11: fffffbfff206313f R12: 0000000000000000 R13: 0000000000000033 R14: 0000000000000200 R15: 1ffff92000720f0c _printk+0xdd/0x130 kernel/printk/printk.c:2504 _btrfs_printk+0x29a/0x320 fs/btrfs/messages.c:236 btrfs_emit_options+0x170e/0x4130 fs/btrfs/super.c:1458 btrfs_fill_super fs/btrfs/super.c:988 [inline] btrfs_get_tree_super fs/btrfs/super.c:1971 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2114 [inline] btrfs_get_tree+0x10a3/0x1980 fs/btrfs/super.c:2148 vfs_get_tree+0x92/0x2a0 fs/super.c:1694 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3765 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3841 do_mount fs/namespace.c:4174 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4367 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f25c9b9e0ca Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f25caa98e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f25caa98ee0 RCX: 00007f25c9b9e0ca RDX: 0000200000000000 RSI: 00002000000015c0 RDI: 00007f25caa98ea0 RBP: 0000200000000000 R08: 00007f25caa98ee0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000015c0 R13: 00007f25caa98ea0 R14: 000000000000559e R15: 0000200000000040