R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 00000000004d02e0 R14: 00000000004c0188 R15: 000000000000002b ================================================================== BUG: KASAN: use-after-free in __fire_sched_in_preempt_notifiers kernel/sched/core.c:2486 [inline] BUG: KASAN: use-after-free in fire_sched_in_preempt_notifiers kernel/sched/core.c:2492 [inline] BUG: KASAN: use-after-free in finish_task_switch+0x78e/0x900 kernel/sched/core.c:2684 Read of size 8 at addr ffff88018fce8d58 by task syz-executor4/15911 CPU: 0 PID: 15911 Comm: syz-executor4 Not tainted 4.19.0-rc4-next-20180921+ #77 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+0x1d3/0x2c4 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_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __fire_sched_in_preempt_notifiers kernel/sched/core.c:2486 [inline] fire_sched_in_preempt_notifiers kernel/sched/core.c:2492 [inline] finish_task_switch+0x78e/0x900 kernel/sched/core.c:2684 context_switch kernel/sched/core.c:2833 [inline] __schedule+0x874/0x1ed0 kernel/sched/core.c:3479 preempt_schedule_irq+0x87/0x110 kernel/sched/core.c:3706 retint_kernel+0x1b/0x2d RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] RIP: 0010:compound_head include/linux/page-flags.h:143 [inline] RIP: 0010:virt_to_head_page include/linux/mm.h:660 [inline] RIP: 0010:qlink_to_cache mm/kasan/quarantine.c:127 [inline] RIP: 0010:qlist_free_all+0x118/0x140 mm/kasan/quarantine.c:163 Code: 57 9d 0f 1f 44 00 00 eb af 48 89 df e8 21 70 77 ff 48 b9 00 00 00 00 00 ea ff ff 48 c1 e8 0c 48 c1 e0 06 48 01 c8 48 8b 50 08 <48> 8d 4a ff 83 e2 01 48 0f 45 c1 4c 8b 78 18 e9 04 ff ff ff 0f 0b RSP: 0018:ffff880196957560 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: ffffea00075c3480 RBX: ffff8801d70d2a80 RCX: ffffea0000000000 RDX: ffffea00076176c8 RSI: ffffffff81384f96 RDI: 0000000000000007 RBP: ffff880196957590 R08: ffff880194edc180 R09: 0000000000000006 R10: 0000000000000000 R11: ffff880194edc180 R12: 0000000000000000 R13: ffff8801c9cbe000 R14: ffff8801d70d2a80 R15: 0000000000000000 quarantine_reduce+0x163/0x1a0 mm/kasan/quarantine.c:259 kasan_kmalloc+0x9b/0xe0 mm/kasan/kasan.c:538 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 slab_post_alloc_hook mm/slab.h:444 [inline] slab_alloc mm/slab.c:3392 [inline] kmem_cache_alloc+0x11b/0x730 mm/slab.c:3552 alloc_inode+0xb2/0x190 fs/inode.c:212 new_inode_pseudo+0x71/0x1a0 fs/inode.c:903 new_inode+0x1c/0x40 fs/inode.c:932 debugfs_get_inode+0x19/0x120 fs/debugfs/inode.c:37 __debugfs_create_file+0xb5/0x400 fs/debugfs/inode.c:354 debugfs_create_file+0x57/0x70 fs/debugfs/inode.c:401 kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:619 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3213 [inline] kvm_dev_ioctl+0xc0a/0x1ae0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3240 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: 0033:0x457679 Code: 1d 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 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa1c029dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa1c029e6d4 RCX: 0000000000457679 RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000006 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004cfe90 R14: 00000000004bfd7b R15: 0000000000000000 Allocated by task 15911: 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:731 [inline] vmx_create_vcpu+0xcf/0x25c0 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:2475 [inline] kvm_vm_ioctl+0x472/0x1d60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2976 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 15907: 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:751 [inline] kvm_put_kvm+0x6c8/0xff0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:772 kvm_vcpu_release+0x7b/0xa0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2406 __fput+0x3bc/0xa70 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 ffff88018fce8d40 which belongs to the cache kvm_vcpu(17:syz4) of size 23872 The buggy address is located 24 bytes inside of 23872-byte region [ffff88018fce8d40, ffff88018fceea80) The buggy address belongs to the page: page:ffffea00063f3a00 count:1 mapcount:0 mapping:ffff8801d90bde40 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0006292a08 ffffea0006e76a08 ffff8801d90bde40 raw: 0000000000000000 ffff88018fce8d40 0000000100000001 ffff88019311c040 page dumped because: kasan: bad access detected page->mem_cgroup:ffff88019311c040 Memory state around the buggy address: ffff88018fce8c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88018fce8c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88018fce8d00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff88018fce8d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88018fce8e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================