L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details. ================================================================== BUG: KASAN: slab-out-of-bounds in search_memslots include/linux/kvm_host.h:1051 [inline] BUG: KASAN: slab-out-of-bounds in __gfn_to_memslot include/linux/kvm_host.h:1063 [inline] BUG: KASAN: slab-out-of-bounds in kvm_vcpu_gfn_to_memslot+0x50e/0x540 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1603 Read of size 8 at addr ffff88809e3bb468 by task syz-executor088/7241 CPU: 1 PID: 7241 Comm: syz-executor088 Not tainted 5.6.0-syzkaller #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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:503 kasan_report+0x33/0x50 mm/kasan/common.c:648 search_memslots include/linux/kvm_host.h:1051 [inline] __gfn_to_memslot include/linux/kvm_host.h:1063 [inline] kvm_vcpu_gfn_to_memslot+0x50e/0x540 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1603 try_async_pf+0x12b/0xac0 arch/x86/kvm/mmu/mmu.c:4097 direct_page_fault+0x27d/0x1d70 arch/x86/kvm/mmu/mmu.c:4146 kvm_mmu_do_page_fault arch/x86/kvm/mmu.h:115 [inline] kvm_mmu_page_fault+0x187/0x15d0 arch/x86/kvm/mmu/mmu.c:5446 vmx_handle_exit+0x2b8/0x1700 arch/x86/kvm/vmx/vmx.c:5953 vcpu_enter_guest+0xfea/0x59d0 arch/x86/kvm/x86.c:8470 vcpu_run arch/x86/kvm/x86.c:8533 [inline] kvm_arch_vcpu_ioctl_run+0x3fb/0x16a0 arch/x86/kvm/x86.c:8755 kvm_vcpu_ioctl+0x493/0xe60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3138 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x440209 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffd115ca0d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440209 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000401a90 R13: 0000000000401b20 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 7241: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:518 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:491 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x61/0xf0 mm/util.c:574 kvmalloc include/linux/mm.h:733 [inline] kvzalloc include/linux/mm.h:741 [inline] kvm_dup_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:1101 [inline] kvm_set_memslot+0x115/0x1530 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1118 __kvm_set_memory_region+0xcf7/0x1320 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1300 kvm_set_memory_region+0x29/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1321 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1333 [inline] kvm_vm_ioctl+0x678/0x23e0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3604 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff88809e3bb000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1128 bytes inside of 2048-byte region [ffff88809e3bb000, ffff88809e3bb800) The buggy address belongs to the page: page:ffffea000278eec0 refcount:1 mapcount:0 mapping:00000000c2601645 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00027b1b08 ffff8880aa001950 ffff8880aa000e00 raw: 0000000000000000 ffff88809e3bb000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809e3bb300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88809e3bb380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88809e3bb400: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ^ ffff88809e3bb480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809e3bb500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================