INFO: task syz.0.343:1384 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.343       state:D stack:0     pid:1384  tgid:1381  ppid:289    flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6016 [inline]
 __schedule+0x1399/0x1fa0 kernel/sched/core.c:7870
 __schedule_loop kernel/sched/core.c:7951 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7966
 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x369/0x650 kernel/sched/completion.c:127
 wait_for_completion_state+0x19/0x40 kernel/sched/completion.c:264
 coredump_wait fs/coredump.c:448 [inline]
 do_coredump+0x8ad/0x2fe0 fs/coredump.c:629
 get_signal+0x11f8/0x14e0 kernel/signal.c:2918
 arch_do_signal_or_restart+0xbc/0x760 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 57c3:0x7f0315216180
RSP: 0003:00007f0315216188 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 00007f0314e51c8e RCX: 00007f0315dd00d0
RDX: 000000000000004a RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000010 R09: 00007f0315216180
R10: 0000000015dd0070 R11: ffffffff00001673 R12: 00007f0315183bb0
R13: 00007f03152161b0 R14: 000000000000004a R15: 000000002b03e9a9
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 4629476e74998a42e0eeb731ff095178aeeee8c1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2ba/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+0xdad/0xf00 kernel/hung_task.c:423
 kthread+0x2c6/0x370 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 2419 Comm: syz.6.579 Not tainted syzkaller #0 4629476e74998a42e0eeb731ff095178aeeee8c1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:unwind_next_frame+0x47/0x750 arch/x86/kernel/unwind_frame.c:273
Code: 00 00 fc ff df 49 89 fe 49 c1 ee 03 41 0f b6 04 16 84 c0 0f 85 f4 05 00 00 83 3b 00 0f 84 5b 05 00 00 4c 89 75 90 4c 8d 73 58 <4d> 89 f5 49 c1 ed 03 41 80 7c 15 00 00 74 12 4c 89 f7 e8 d2 15 9b
RSP: 0018:ffffc900007ef3a8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffc900007ef428 RCX: 00000000007ef400
RDX: dffffc0000000000 RSI: ffffffff85a135f7 RDI: ffffc900007ef428
RBP: ffffc900007ef418 R08: ffffc900007ef4f0 R09: ffffc900007ef4e8
R10: 000000000000000b R11: ffffffff8175d830 R12: ffff88811e61a600
R13: 1ffff11023cc3580 R14: ffffc900007ef480 R15: ffffc900007ef428
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd3a6b47e20 CR3: 000000010c738000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 arch_stack_walk+0x138/0x170 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 save_stack+0x125/0x240 mm/page_owner.c:174
 __reset_page_owner+0x79/0x450 mm/page_owner.c:315
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1390 [inline]
 free_unref_page+0xbcf/0xf80 mm/page_alloc.c:2876
 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5385
 vfree+0x3ea/0x5b0 mm/vmalloc.c:3398
 kcov_put kernel/kcov.c:439 [inline]
 kcov_close+0x2c/0x70 kernel/kcov.c:535
 __fput+0x1fb/0xa00 fs/file_table.c:429
 ____fput+0x20/0x30 fs/file_table.c:457
 task_work_run+0x1e8/0x260 kernel/task_work.c:246
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x9ad/0x2720 kernel/exit.c:954
 do_group_exit+0x229/0x2f0 kernel/exit.c:1096
 get_signal+0x1398/0x14e0 kernel/signal.c:2933
 arch_do_signal_or_restart+0xbc/0x760 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fed9135d04e
Code: Unable to access opcode bytes at 0x7fed9135d024.
RSP: 002b:00007fed92219f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007fed9221a6c0 RCX: 00007fed9135d04e
RDX: 00007fed92219fb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fed91432c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fed91616038 R14: 00007fed91615fa0 R15: 00007ffc9ca311c8
 </TASK>