IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xffffff26d29935f5 TPR Threshold = 0x00 EPT pointer = 0x00000001d8de201e ================================================================== BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:681 [inline] BUG: KASAN: use-after-free in hlist_del include/linux/list.h:686 [inline] BUG: KASAN: use-after-free in preempt_notifier_unregister+0x235/0x250 kernel/sched/core.c:2472 Write of size 8 at addr ffff880190e58990 by task syz-executor2/21149 CPU: 1 PID: 21149 Comm: syz-executor2 Not tainted 4.19.0-rc1-next-20180829+ #50 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+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:438 __hlist_del include/linux/list.h:681 [inline] hlist_del include/linux/list.h:686 [inline] preempt_notifier_unregister+0x235/0x250 kernel/sched/core.c:2472 vcpu_put+0x25/0x30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:173 kvm_arch_vcpu_ioctl_run+0xafc/0x16d0 arch/x86/kvm/x86.c:7879 kvm_vcpu_ioctl+0x7b8/0x1280 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2590 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f9a3cdc2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9a3cdc36d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000009 RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004ceea8 R14: 00000000004c5529 R15: 0000000000000001 Allocated by task 21133: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x710 mm/slab.c:3554 kmem_cache_zalloc include/linux/slab.h:697 [inline] vmx_create_vcpu+0xcf/0x2830 arch/x86/kvm/vmx.c:10954 kvm_arch_vcpu_create+0xe5/0x220 arch/x86/kvm/x86.c:8434 kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:2476 [inline] kvm_vm_ioctl+0x488/0x1d80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2977 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 21129: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 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+0x86/0x280 mm/slab.c:3756 vmx_free_vcpu+0x26b/0x300 arch/x86/kvm/vmx.c:10948 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8420 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8870 [inline] kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:8967 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:752 [inline] kvm_put_kvm+0x73f/0x1060 arch/x86/kvm/../../../virt/kvm/kvm_main.c:773 kvm_vcpu_release+0x7b/0xa0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2407 __fput+0x376/0x8a0 fs/file_table.c:279 ____fput+0x15/0x20 fs/file_table.c:312 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff880190e58980 which belongs to the cache kvm_vcpu of size 23872 The buggy address is located 16 bytes inside of 23872-byte region [ffff880190e58980, ffff880190e5e6c0) The buggy address belongs to the page: page:ffffea0006439600 count:1 mapcount:0 mapping:ffff8801d4cb5c40 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffffea0006376208 ffffea00074ac608 ffff8801d4cb5c40 raw: 0000000000000000 ffff880190e58980 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff880190e58880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff880190e58900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff880190e58980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880190e58a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880190e58a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================