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 ffff8881f55b7200 by task syz-executor.5/9267 CPU: 1 PID: 9267 Comm: syz-executor.5 Not tainted 5.4.111-syzkaller-00138-g3c5dbcf40ba8 #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:00007fb5ffdfb188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000020000240 RSI: 000000004010ae68 RDI: 0000000000000004 RBP: 00007fb5ffdfb1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffdef2c744f R14: 00007fb5ffdfb300 R15: 0000000000022000 Allocated by task 9267: 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 9267: 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 ffff8881f55b7200 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 0 bytes inside of 64-byte region [ffff8881f55b7200, ffff8881f55b7240) The buggy address belongs to the page: page:ffffea0007d56dc0 refcount:1 mapcount:0 mapping:ffff8881f5c03180 index:0x0 flags: 0x8000000000000200(slab) raw: 8000000000000200 ffffea0007965c80 0000000200000002 ffff8881f5c03180 raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881f55b7100: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8881f55b7180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8881f55b7200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8881f55b7280: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff8881f55b7300: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 9267 Comm: syz-executor.5 Tainted: G B 5.4.111-syzkaller-00138-g3c5dbcf40ba8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvm_iodevice_destructor include/kvm/iodev.h:60 [inline] RIP: 0010:kvm_vm_ioctl_unregister_coalesced_mmio+0x28d/0x3a0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:192 Code: e8 18 58 ff ff 4c 89 e0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 e7 e8 f2 48 8c 00 49 8b 1c 24 48 83 c3 10 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 d4 48 8c 00 4c 8b 33 4d 85 f6 48 RSP: 0018:ffff8881de587818 EFLAGS: 00010202 RAX: 0000000000000002 RBX: 0000000000000010 RCX: ffffffff8107b23e RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88819f86c310 RBP: 0000000000000000 R08: ffffffff81070a93 R09: fffffbfff0dc3bd1 R10: fffffbfff0dc3bd1 R11: 0000000000000000 R12: ffff88819f86c310 R13: ffff8881de587afc R14: 0000000000000000 R15: dffffc0000000000 FS: 00007fb5ffdfb700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002b47b38 CR3: 00000001e65f2000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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:00007fb5ffdfb188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000020000240 RSI: 000000004010ae68 RDI: 0000000000000004 RBP: 00007fb5ffdfb1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffdef2c744f R14: 00007fb5ffdfb300 R15: 0000000000022000 Modules linked in: ---[ end trace 187cc065bf6c7aab ]--- RIP: 0010:kvm_iodevice_destructor include/kvm/iodev.h:60 [inline] RIP: 0010:kvm_vm_ioctl_unregister_coalesced_mmio+0x28d/0x3a0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:192 Code: e8 18 58 ff ff 4c 89 e0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 e7 e8 f2 48 8c 00 49 8b 1c 24 48 83 c3 10 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 d4 48 8c 00 4c 8b 33 4d 85 f6 48 RSP: 0018:ffff8881de587818 EFLAGS: 00010202 RAX: 0000000000000002 RBX: 0000000000000010 RCX: ffffffff8107b23e RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88819f86c310 RBP: 0000000000000000 R08: ffffffff81070a93 R09: fffffbfff0dc3bd1 R10: fffffbfff0dc3bd1 R11: 0000000000000000 R12: ffff88819f86c310 R13: ffff8881de587afc R14: 0000000000000000 R15: dffffc0000000000 FS: 00007fb5ffdfb700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002b47b38 CR3: 00000001e65f2000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400