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_gfn_to_hva_cache_init+0x5fb/0x670 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2443 Read of size 8 at addr ffff8880a66ca468 by task syz-executor781/7036 CPU: 0 PID: 7036 Comm: syz-executor781 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:382 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511 kasan_report+0x33/0x50 mm/kasan/common.c:625 search_memslots include/linux/kvm_host.h:1051 [inline] __gfn_to_memslot include/linux/kvm_host.h:1063 [inline] __kvm_gfn_to_hva_cache_init+0x5fb/0x670 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2443 kvm_lapic_set_vapic_addr+0x88/0x180 arch/x86/kvm/lapic.c:2662 kvm_arch_vcpu_ioctl+0xf0d/0x2c20 arch/x86/kvm/x86.c:4386 kvm_vcpu_ioctl+0x866/0xe60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3291 kvm_vcpu_compat_ioctl+0x1ab/0x350 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3334 __do_compat_sys_ioctl fs/ioctl.c:857 [inline] __se_compat_sys_ioctl fs/ioctl.c:808 [inline] __ia32_compat_sys_ioctl+0x23d/0x2b0 fs/ioctl.c:808 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe90 arch/x86/entry/common.c:396 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Allocated by task 7036: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x61/0xf0 mm/util.c:574 kvmalloc include/linux/mm.h:757 [inline] kvzalloc include/linux/mm.h:765 [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 __x86_set_memory_region+0x2a3/0x5a0 arch/x86/kvm/x86.c:9846 alloc_apic_access_page arch/x86/kvm/vmx/vmx.c:3540 [inline] vmx_create_vcpu+0x2107/0x2b40 arch/x86/kvm/vmx/vmx.c:6768 kvm_arch_vcpu_create+0x6ef/0xb80 arch/x86/kvm/x86.c:9366 kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:3030 [inline] kvm_vm_ioctl+0x15f7/0x23e0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3585 kvm_vm_compat_ioctl+0x125/0x240 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3798 __do_compat_sys_ioctl fs/ioctl.c:857 [inline] __se_compat_sys_ioctl fs/ioctl.c:808 [inline] __ia32_compat_sys_ioctl+0x23d/0x2b0 fs/ioctl.c:808 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe90 arch/x86/entry/common.c:396 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Freed by task 6955: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 tty_port_destructor drivers/tty/tty_port.c:264 [inline] kref_put include/linux/kref.h:65 [inline] tty_port_put drivers/tty/tty_port.c:272 [inline] tty_port_put+0x16a/0x1d0 drivers/tty/tty_port.c:269 vt_disallocate drivers/tty/vt/vt_ioctl.c:320 [inline] vt_ioctl+0x1c67/0x26b0 drivers/tty/vt/vt_ioctl.c:828 tty_ioctl+0xedc/0x1440 drivers/tty/tty_io.c:2656 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 The buggy address belongs to the object at ffff8880a66ca000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1128 bytes inside of 2048-byte region [ffff8880a66ca000, ffff8880a66ca800) The buggy address belongs to the page: page:ffffea000299b280 refcount:1 mapcount:0 mapping:0000000080985d54 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea000299b1c8 ffffea000299b2c8 ffff8880aa000e00 raw: 0000000000000000 ffff8880a66ca000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a66ca300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a66ca380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a66ca400: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ^ ffff8880a66ca480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a66ca500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================