syzbot

INFO: task syz.4.1439:11321 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.4.1439      state:D stack:25768 pid:11321 tgid:11320 ppid:5622   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5504 [inline]
 __schedule+0x125c/0x6730 kernel/sched/core.c:7228
 __schedule_loop kernel/sched/core.c:7307 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7322
 io_schedule+0x8a/0xf0 kernel/sched/core.c:8150
 folio_wait_bit_common+0x414/0xa70 mm/filemap.c:1324
 folio_lock include/linux/pagemap.h:1159 [inline]
 migrate_folio_unmap mm/migrate.c:1250 [inline]
 migrate_pages_batch+0x7a1/0x45c0 mm/migrate.c:1907
 migrate_pages_sync+0x4db/0x880 mm/migrate.c:2051
 migrate_pages+0x1a83/0x2850 mm/migrate.c:2133
 compact_zone+0x243c/0x4420 mm/compaction.c:2669
 compact_node+0x17f/0x2c0 mm/compaction.c:2938
 compact_nodes mm/compaction.c:2960 [inline]
 sysctl_compaction_handler mm/compaction.c:3011 [inline]
 sysctl_compaction_handler+0x141/0x210 mm/compaction.c:2998
 proc_sys_call_handler+0x47f/0x5a0 fs/proc/proc_sysctl.c:600
 iter_file_splice_write+0x830/0x10b0 fs/splice.c:736
 do_splice_from fs/splice.c:936 [inline]
 direct_splice_actor+0x192/0x690 fs/splice.c:1159
 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x174/0x240 fs/splice.c:1228
 do_sendfile+0xadc/0xe20 fs/read_write.c:1371
 __do_sys_sendfile64 fs/read_write.c:1426 [inline]
 __se_sys_sendfile64 fs/read_write.c:1418 [inline]
 __x64_sys_sendfile64+0x154/0x220 fs/read_write.c:1418
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff98259ce59
RSP: 002b:00007ff9834d3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007ff982815fa0 RCX: 00007ff98259ce59
RDX: 00002000000000c0 RSI: 0000000000000007 RDI: 0000000000000008
RBP: 00007ff982632e6f R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff982816038 R14: 00007ff982815fa0 R15: 00007ffe07a8bbe8
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 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:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 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:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: b6 88 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 f8 14 00 fb f4 <e9> fc 48 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197e00 EFLAGS: 00000246
RAX: 0000000003f26fec RBX: ffff88801e2d2540 RCX: ffffffff8b96a2d5
RDX: 0000000000000001 RSI: ffffffff8c1d2680 RDI: ffffffff81de2aa7
RBP: ffffed1003c5a4a8 R08: 0000000000000000 R09: ffffed10170a678d
R10: ffff8880b8533c6b R11: ffffffff81d4ff9c R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000032fc4 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88812441a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5f025e8158 CR3: 000000007c24c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x158
 </TASK>