INFO: task syz.4.3068:8460 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.3068 state:D stack:0 pid:8460 tgid:8459 ppid:3760 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 super_lock+0x150/0x300 fs/super.c:115 super_lock_shared fs/super.c:140 [inline] iterate_supers+0x8a/0x560 fs/super.c:934 ksys_sync+0x95/0x160 fs/sync.c:103 __ia32_sys_sync+0x12/0x20 fs/sync.c:114 x64_sys_call+0x2a58/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:163 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f238318ebe9 RSP: 002b:00007f23840ce038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f23833b5fa0 RCX: 00007f238318ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f23833b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f23833b6038 R14: 00007f23833b5fa0 R15: 00007ffeb7d1dda8 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 a29bcd2d578c4b9493db917853c72486663e8fa1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:423 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12709 Comm: syz.3.4589 Not tainted syzkaller #0 a29bcd2d578c4b9493db917853c72486663e8fa1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:io_serial_out+0x85/0xd0 drivers/tty/serial/8250/8250_port.c:413 Code: fe 44 89 e1 41 d3 e6 49 83 c7 08 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 24 c8 c3 fe 45 03 37 89 d8 44 89 f2 ee <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 e1 80 e1 07 RSP: 0018:ffffc9000f72f308 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 00000000000010f4 RDI: 00000000000010f5 RBP: ffffc9000f72f330 R08: 0000000000000003 R09: 0000000000000004 R10: 0000000000000000 R11: ffffffff83184420 R12: 0000000000000000 R13: dffffc0000000000 R14: 00000000000003f9 R15: ffffffff889ecde8 FS: 00007f5cd0d856c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd25eb2b88 CR3: 000000014490e000 CR4: 00000000003526b0 DR0: 0000000001400000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: serial_out drivers/tty/serial/8250/8250.h:142 [inline] serial8250_clear_IER drivers/tty/serial/8250/8250_port.c:-1 [inline] serial8250_console_write+0x3a9/0x2130 drivers/tty/serial/8250/8250_port.c:3387 univ8250_console_write+0x6f/0xb0 drivers/tty/serial/8250/8250_core.c:396 console_emit_next_record kernel/printk/printk.c:3151 [inline] console_flush_all+0x5e6/0xaa0 kernel/printk/printk.c:3239 __console_flush_and_unlock kernel/printk/printk.c:3298 [inline] console_unlock+0xe9/0x270 kernel/printk/printk.c:3338 vprintk_emit+0x27c/0x640 kernel/printk/printk.c:2462 dev_vprintk_emit+0x33b/0x400 drivers/base/core.c:4962 dev_printk_emit+0xe1/0x130 drivers/base/core.c:4973 __dev_printk+0x17f/0x1b0 drivers/base/core.c:4985 _dev_err+0x10b/0x160 drivers/base/core.c:5028 raw_ioctl_ep_enable drivers/usb/gadget/legacy/raw_gadget.c:886 [inline] raw_ioctl+0x27d1/0x3600 drivers/usb/gadget/legacy/raw_gadget.c:1318 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0x135/0x1b0 fs/ioctl.c:893 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:893 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f5ccff8e7eb Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007f5cd0d82f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5cd02e0320 RCX: 00007f5ccff8e7eb RDX: 00007f5cd02e076c RSI: 0000000040095505 RDI: 0000000000000008 RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000008 R11: 0000000000000246 R12: 00007f5cd02e076e R13: 00007f5cd02e076c R14: 0000000000000000 R15: 0000000000000000