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 ffff8880a666a468 by task syz-executor772/7022 CPU: 0 PID: 7022 Comm: syz-executor772 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_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: 0033:0x440359 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:00007ffdeffdb0b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440359 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000401be0 R13: 0000000000401c70 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 7022: 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:739 [inline] kvzalloc include/linux/mm.h:747 [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:9845 alloc_apic_access_page arch/x86/kvm/vmx/vmx.c:3544 [inline] vmx_create_vcpu+0x2107/0x2b40 arch/x86/kvm/vmx/vmx.c:6772 kvm_arch_vcpu_create+0x6ef/0xb80 arch/x86/kvm/x86.c:9365 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 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 6931: 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 skb_free_head+0x8b/0xa0 net/core/skbuff.c:590 skb_release_data+0x42e/0x8b0 net/core/skbuff.c:610 skb_release_all+0x46/0x60 net/core/skbuff.c:664 __kfree_skb net/core/skbuff.c:678 [inline] consume_skb net/core/skbuff.c:837 [inline] consume_skb+0xf3/0x400 net/core/skbuff.c:831 unix_stream_read_generic+0x17e1/0x1c80 net/unix/af_unix.c:2416 unix_stream_recvmsg+0xb1/0xf0 net/unix/af_unix.c:2474 sock_recvmsg_nosec net/socket.c:886 [inline] sock_recvmsg net/socket.c:904 [inline] sock_recvmsg+0xca/0x110 net/socket.c:900 sock_read_iter+0x2c7/0x3d0 net/socket.c:982 call_read_iter include/linux/fs.h:1901 [inline] new_sync_read+0x64d/0x7a0 fs/read_write.c:414 __vfs_read+0xc9/0x100 fs/read_write.c:427 vfs_read+0x1f0/0x420 fs/read_write.c:461 ksys_read+0x1ee/0x250 fs/read_write.c:587 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 ffff8880a666a000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1128 bytes inside of 2048-byte region [ffff8880a666a000, ffff8880a666a800) The buggy address belongs to the page: page:ffffea0002999a80 refcount:1 mapcount:0 mapping:00000000f67550cf index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002999a08 ffffea0002998dc8 ffff8880aa000e00 raw: 0000000000000000 ffff8880a666a000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a666a300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a666a380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a666a400: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ^ ffff8880a666a480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a666a500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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