INFO: task syz.6.4093:27962 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.4093 state:D stack:24976 pid:27962 tgid:27952 ppid:23113 task_flags:0x400140 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 io_schedule+0x7f/0xd0 kernel/sched/core.c:8150 folio_wait_bit_common+0x836/0xbc0 mm/filemap.c:1324 folio_lock include/linux/pagemap.h:1159 [inline] migrate_folio_unmap mm/migrate.c:1250 [inline] migrate_pages_batch+0x2403/0x4e50 mm/migrate.c:1907 migrate_pages_sync mm/migrate.c:2051 [inline] migrate_pages+0x1fab/0x2920 mm/migrate.c:2133 compact_zone+0x310e/0x4a30 mm/compaction.c:2669 compact_node mm/compaction.c:2938 [inline] compact_nodes mm/compaction.c:2960 [inline] sysctl_compaction_handler+0x3f3/0x880 mm/compaction.c:3011 proc_sys_call_handler+0x4c6/0x830 fs/proc/proc_sysctl.c:600 iter_file_splice_write+0xa31/0x1240 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x101/0x160 fs/splice.c:1159 splice_direct_to_actor+0x57b/0xcb0 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x195/0x290 fs/splice.c:1228 do_sendfile+0x52e/0x7c0 fs/read_write.c:1371 __do_sys_sendfile64 fs/read_write.c:1426 [inline] __se_sys_sendfile64+0xdf/0x1a0 fs/read_write.c:1418 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: 0033:0x7fdc35f9ce59 RSP: 002b:00007fdc36e71028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fdc36215fa0 RCX: 00007fdc35f9ce59 RDX: 00002000000000c0 RSI: 0000000000000006 RDI: 0000000000000007 RBP: 00007fdc36032e6f R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdc36216038 R14: 00007fdc36215fa0 R15: 00007ffe926bf238 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: 30816 Comm: syz-executor 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:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401 Code: e8 7e 2c 7c fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 6f ad e9 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 a5 38 c6 fb cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90004ff6628 EFLAGS: 00000002 RAX: 1ffffffff34faf00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: dffffc0000000000 R08: ffff888026460237 R09: 1ffff11004c8c046 R10: dffffc0000000000 R11: ffffffff854a07e0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff9a7d7de0 R15: 0000000000000000 FS: 000055555f057500(0000) GS:ffff888125253000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c499eae CR3: 0000000025a70000 CR4: 0000000000350ef0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:1973 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3210 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3275 [inline] serial8250_console_write+0x1373/0x1bd0 drivers/tty/serial/8250/8250_port.c:3360 console_emit_next_record kernel/printk/printk.c:3183 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x6ea/0xaf0 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 _printk+0xdd/0x130 kernel/printk/printk.c:2504 vlan_vid0_add net/8021q/vlan.c:370 [inline] vlan_device_event+0x1c68/0x1f00 net/8021q/vlan.c:413 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline] call_netdevice_notifiers net/core/dev.c:2302 [inline] __dev_notify_flags+0x1aa/0x310 net/core/dev.c:9793 netif_change_flags+0xde/0x1b0 net/core/dev.c:9822 do_setlink+0xdd6/0x4670 net/core/rtnetlink.c:3207 rtnl_changelink net/core/rtnetlink.c:3841 [inline] __rtnl_newlink net/core/rtnetlink.c:4014 [inline] rtnl_newlink+0x15c2/0x1bd0 net/core/rtnetlink.c:4151 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7068 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2252 __do_sys_sendto net/socket.c:2259 [inline] __se_sys_sendto net/socket.c:2255 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2255 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: 0033:0x7feb4875d68e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffd331a00b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055555f057500 RCX: 00007feb4875d68e RDX: 0000000000000030 RSI: 00007feb49543610 RDI: 0000000000000006 RBP: 0000000000000001 R08: 00007ffd331a0134 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 0000000000000000 R14: 00007feb49543610 R15: 0000000000000000