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BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:704 [inline]
BUG: KASAN: use-after-free in preempt_notifier_register+0x1ec/0x200 kernel/sched/core.c:2460
Write of size 8 at addr ffff880195df0c50 by task syz-executor0/26087

CPU: 0 PID: 26087 Comm: syz-executor0 Not tainted 4.19.0-rc4+ #146
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:438
 hlist_add_head include/linux/list.h:704 [inline]
 preempt_notifier_register+0x1ec/0x200 kernel/sched/core.c:2460
 vcpu_load+0x2a/0x70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:163
 vmx_free_vcpu_nested arch/x86/kvm/vmx.c:10930 [inline]
 vmx_free_vcpu+0x18d/0x300 arch/x86/kvm/vmx.c:10944
 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8438 [inline]
 kvm_free_vcpus arch/x86/kvm/x86.c:8888 [inline]
 kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:8985
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:752 [inline]
 kvm_put_kvm+0x6c8/0xff0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:773
 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:784
 __fput+0x385/0xa30 fs/file_table.c:278
 ____fput+0x15/0x20 fs/file_table.c:309
 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x1ad7/0x2610 kernel/exit.c:867
 do_group_exit+0x177/0x440 kernel/exit.c:970
 get_signal+0x8b0/0x1980 kernel/signal.c:2513
 do_signal+0x9c/0x21e0 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_32_irqs_on arch/x86/entry/common.c:341 [inline]
 do_fast_syscall_32+0xcd5/0xfb2 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fe4ca9
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 0c 24 c3 8b 1c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5fe00cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: 000000000000000a RBX: 0000000000000009 RCX: 000000000000ae01
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 26087:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554
 kmem_cache_zalloc include/linux/slab.h:697 [inline]
 vmx_create_vcpu+0xcf/0x25e0 arch/x86/kvm/vmx.c:10954
 kvm_arch_vcpu_create+0xe5/0x220 arch/x86/kvm/x86.c:8452
 kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:2476 [inline]
 kvm_vm_ioctl+0x470/0x1d40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2977
 kvm_vm_compat_ioctl+0x143/0x430 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3170
 __do_compat_sys_ioctl fs/compat_ioctl.c:1419 [inline]
 __se_compat_sys_ioctl fs/compat_ioctl.c:1365 [inline]
 __ia32_compat_sys_ioctl+0x20e/0x630 fs/compat_ioctl.c:1365
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 26087:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x83/0x290 mm/slab.c:3756
 vmx_free_vcpu+0x26b/0x300 arch/x86/kvm/vmx.c:10948
 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8438 [inline]
 kvm_free_vcpus arch/x86/kvm/x86.c:8888 [inline]
 kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:8985
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:752 [inline]
 kvm_put_kvm+0x6c8/0xff0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:773
 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:784
 __fput+0x385/0xa30 fs/file_table.c:278
 ____fput+0x15/0x20 fs/file_table.c:309
 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x1ad7/0x2610 kernel/exit.c:867
 do_group_exit+0x177/0x440 kernel/exit.c:970
 get_signal+0x8b0/0x1980 kernel/signal.c:2513
 do_signal+0x9c/0x21e0 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_32_irqs_on arch/x86/entry/common.c:341 [inline]
 do_fast_syscall_32+0xcd5/0xfb2 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

The buggy address belongs to the object at ffff880195df0c40
 which belongs to the cache kvm_vcpu(81:syz0) of size 23872
The buggy address is located 16 bytes inside of
 23872-byte region [ffff880195df0c40, ffff880195df6980)
The buggy address belongs to the page:
page:ffffea0006577c00 count:1 mapcount:0 mapping:ffff8801d8542980 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea0005c4f808 ffffea0006644208 ffff8801d8542980
raw: 0000000000000000 ffff880195df0c40 0000000100000001 ffff8801c26aa6c0
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8801c26aa6c0

Memory state around the buggy address:
 ffff880195df0b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff880195df0b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff880195df0c00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                                 ^
 ffff880195df0c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff880195df0d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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