R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffdbc02d7cf R14: 00007f9a625dc300 R15: 0000000000022000 kvm: failed to shrink bus, removing it completely ================================================================== BUG: KASAN: use-after-free in kvm_vm_ioctl_unregister_coalesced_mmio+0xe6/0x3a0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:187 Read of size 8 at addr ffff88819954f000 by task syz-executor.2/5404 CPU: 0 PID: 5404 Comm: syz-executor.2 Not tainted 5.4.106-syzkaller-00700-g63fc7efda14e #0 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+0x1d8/0x24e lib/dump_stack.c:118 print_address_description+0x9b/0x650 mm/kasan/report.c:384 __kasan_report+0x182/0x260 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:641 kvm_vm_ioctl_unregister_coalesced_mmio+0xe6/0x3a0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:187 kvm_vm_ioctl+0x947/0x1a40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3428 do_vfs_ioctl+0x76a/0x1720 fs/ioctl.c:47 ksys_ioctl fs/ioctl.c:742 [inline] __do_sys_ioctl fs/ioctl.c:749 [inline] __se_sys_ioctl fs/ioctl.c:747 [inline] __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x466459 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9a625dc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000020000240 RSI: 000000004010ae68 RDI: 0000000000000006 RBP: 00007f9a625dc1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffdbc02d7cf R14: 00007f9a625dc300 R15: 0000000000022000 Allocated by task 5404: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x137/0x1e0 mm/kasan/common.c:517 kmem_cache_alloc_trace+0x139/0x2b0 mm/slub.c:2848 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] kvm_vm_ioctl_register_coalesced_mmio+0x86/0x310 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:150 kvm_vm_ioctl+0x7f2/0x1a40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3419 do_vfs_ioctl+0x76a/0x1720 fs/ioctl.c:47 ksys_ioctl fs/ioctl.c:742 [inline] __do_sys_ioctl fs/ioctl.c:749 [inline] __se_sys_ioctl fs/ioctl.c:747 [inline] __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 5404: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:333 [inline] __kasan_slab_free+0x18a/0x240 mm/kasan/common.c:475 slab_free_hook mm/slub.c:1454 [inline] slab_free_freelist_hook+0x7b/0x150 mm/slub.c:1492 slab_free mm/slub.c:3072 [inline] kfree+0xe0/0x660 mm/slub.c:4061 kvm_iodevice_destructor include/kvm/iodev.h:61 [inline] kvm_io_bus_unregister_dev+0x377/0x470 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4050 kvm_vm_ioctl_unregister_coalesced_mmio+0x268/0x3a0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:190 kvm_vm_ioctl+0x947/0x1a40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3428 do_vfs_ioctl+0x76a/0x1720 fs/ioctl.c:47 ksys_ioctl fs/ioctl.c:742 [inline] __do_sys_ioctl fs/ioctl.c:749 [inline] __se_sys_ioctl fs/ioctl.c:747 [inline] __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88819954f000 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 0 bytes inside of 64-byte region [ffff88819954f000, ffff88819954f040) The buggy address belongs to the page: page:ffffea00066553c0 refcount:1 mapcount:0 mapping:ffff8881f5c03180 index:0x0 flags: 0x8000000000000200(slab) raw: 8000000000000200 dead000000000100 dead000000000122 ffff8881f5c03180 raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88819954ef00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88819954ef80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff88819954f000: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff88819954f080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88819954f100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== list_del corruption, ffff88819954f000->prev is LIST_POISON2 (dead000000000122) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:50! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 5404 Comm: syz-executor.2 Tainted: G B 5.4.106-syzkaller-00700-g63fc7efda14e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__list_del_entry_valid+0xce/0x100 lib/list_debug.c:48 Code: 5c 41 5e 41 5f c3 48 c7 c7 a0 58 03 85 4c 89 f6 31 c0 e8 11 e7 22 ff 0f 0b 48 c7 c7 00 59 03 85 4c 89 f6 31 c0 e8 fe e6 22 ff <0f> 0b 48 c7 c7 60 59 03 85 4c 89 f6 31 c0 e8 eb e6 22 ff 0f 0b 48 RSP: 0000:ffff8881a41cf7b8 EFLAGS: 00010246 RAX: 000000000000004e RBX: ffff8881e6ea6000 RCX: 54faabfb3487bc00 RDX: ffffc9000cf0e000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffff88819954f010 R08: ffffffff814e88c7 R09: ffffed103edc5e08 R10: ffffed103edc5e08 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8881a41cfafc R14: ffff88819954f000 R15: dead000000000122 FS: 00007f9a625dc700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31522000 CR3: 000000019ca4b000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_del_entry include/linux/list.h:131 [inline] list_del include/linux/list.h:139 [inline] coalesced_mmio_destructor+0x28/0x100 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:100 kvm_iodevice_destructor include/kvm/iodev.h:61 [inline] kvm_vm_ioctl_unregister_coalesced_mmio+0x2b8/0x3a0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:192 kvm_vm_ioctl+0x947/0x1a40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3428 do_vfs_ioctl+0x76a/0x1720 fs/ioctl.c:47 ksys_ioctl fs/ioctl.c:742 [inline] __do_sys_ioctl fs/ioctl.c:749 [inline] __se_sys_ioctl fs/ioctl.c:747 [inline] __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x466459 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9a625dc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000020000240 RSI: 000000004010ae68 RDI: 0000000000000006 RBP: 00007f9a625dc1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffdbc02d7cf R14: 00007f9a625dc300 R15: 0000000000022000 Modules linked in: ---[ end trace 07d13194ca4f7bb9 ]--- RIP: 0010:__list_del_entry_valid+0xce/0x100 lib/list_debug.c:48 Code: 5c 41 5e 41 5f c3 48 c7 c7 a0 58 03 85 4c 89 f6 31 c0 e8 11 e7 22 ff 0f 0b 48 c7 c7 00 59 03 85 4c 89 f6 31 c0 e8 fe e6 22 ff <0f> 0b 48 c7 c7 60 59 03 85 4c 89 f6 31 c0 e8 eb e6 22 ff 0f 0b 48 RSP: 0000:ffff8881a41cf7b8 EFLAGS: 00010246 RAX: 000000000000004e RBX: ffff8881e6ea6000 RCX: 54faabfb3487bc00 RDX: ffffc9000cf0e000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffff88819954f010 R08: ffffffff814e88c7 R09: ffffed103edc5e08 R10: ffffed103edc5e08 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8881a41cfafc R14: ffff88819954f000 R15: dead000000000122 FS: 00007f9a625dc700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31522000 CR3: 000000019ca4b000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400