RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000003
==================================================================
RBP: 00007fc6074761d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
BUG: KASAN: use-after-free in kvm_vm_ioctl_unregister_coalesced_mmio+0x217/0x280 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:178
R13: 00007ffe71d2379f R14: 00007fc607476300 R15: 0000000000022000
Read of size 8 at addr ffff8880966dd600 by task syz-executor.0/8818

CPU: 0 PID: 8818 Comm: syz-executor.0 Not tainted 4.14.218-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'.
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
 kvm_vm_ioctl_unregister_coalesced_mmio+0x217/0x280 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:178
 kvm_vm_ioctl+0x601/0x13e0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3096
netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'.
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x465b09
RSP: 002b:00007f110ce43188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09
RDX: 00000000200000c0 RSI: 000000004010ae68 RDI: 0000000000000004
RBP: 00007f110ce431d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff6a0aabaf R14: 00007f110ce43300 R15: 0000000000022000

Allocated by task 8818:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618
 kmalloc include/linux/slab.h:488 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 kvm_vm_ioctl_register_coalesced_mmio+0x51/0x330 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:146
 kvm_vm_ioctl+0xa81/0x13e0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3087
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 8818:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xc9/0x250 mm/slab.c:3815
 kvm_iodevice_destructor include/kvm/iodev.h:73 [inline]
 kvm_io_bus_unregister_dev.cold+0xd8/0xf8 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3719
 kvm_vm_ioctl_unregister_coalesced_mmio+0x17d/0x280 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:180
 kvm_vm_ioctl+0x601/0x13e0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3096
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

The buggy address belongs to the object at ffff8880966dd600
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 0 bytes inside of
 64-byte region [ffff8880966dd600, ffff8880966dd640)
The buggy address belongs to the page:
page:ffffea000259b740 count:1 mapcount:0 mapping:ffff8880966dd000 index:0xffff8880966dda00
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffff8880966dd000 ffff8880966dda00 0000000100000018
raw: ffffea00028d83e0 ffffea00029535e0 ffff88813fe80340 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880966dd500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880966dd580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8880966dd600: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff8880966dd680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880966dd700: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
==================================================================