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BUG: KMSAN: kernel-infoleak in __copy_to_user include/linux/uaccess.h:121 [inline]
BUG: KMSAN: kernel-infoleak in __kvm_write_guest_page+0x2cc/0x4a0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1855
CPU: 1 PID: 10146 Comm: syz-executor0 Not tainted 4.20.0-rc5+ #2
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+0x1c9/0x220 lib/dump_stack.c:113
 kmsan_report+0x12d/0x290 mm/kmsan/kmsan.c:682
 kmsan_internal_check_memory+0x9e0/0xa60 mm/kmsan/kmsan.c:768
 kmsan_copy_to_user+0x8d/0xa0 mm/kmsan/kmsan_hooks.c:604
 __copy_to_user include/linux/uaccess.h:121 [inline]
 __kvm_write_guest_page+0x2cc/0x4a0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1855
 kvm_vcpu_write_guest_page arch/x86/kvm/../../../virt/kvm/kvm_main.c:1876 [inline]
 kvm_vcpu_write_guest+0x77a/0x920 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1910
 kvm_write_guest_virt_helper arch/x86/kvm/x86.c:5086 [inline]
 emulator_write_std+0x391/0x4d0 arch/x86/kvm/x86.c:5110
 segmented_write_std arch/x86/kvm/emulate.c:853 [inline]
 em_fxsave+0x7d2/0x850 arch/x86/kvm/emulate.c:4073
 x86_emulate_insn+0x24c5/0xa660 arch/x86/kvm/emulate.c:5601
 x86_emulate_instruction+0x1152/0x7520 arch/x86/kvm/x86.c:6367
 kvm_mmu_page_fault+0xd00/0x28e0 arch/x86/kvm/mmu.c:5351
 handle_ept_violation+0x585/0x5c0 arch/x86/kvm/vmx.c:7720
 vmx_handle_exit+0x1699/0x9be0 arch/x86/kvm/vmx.c:10632
 vcpu_enter_guest arch/x86/kvm/x86.c:7811 [inline]
 vcpu_run arch/x86/kvm/x86.c:7874 [inline]
 kvm_arch_vcpu_ioctl_run+0xa787/0x117f0 arch/x86/kvm/x86.c:8074
 kvm_vcpu_ioctl+0x107b/0x1d80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2596
 do_vfs_ioctl+0xf36/0x2d30 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718
 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718
 do_syscall_64+0xcd/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457659
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fa1c5a4ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457659
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa1c5a4b6d4
R13: 00000000004c0505 R14: 00000000004d1580 R15: 00000000ffffffff

Local variable description: ----fx_state@em_fxsave
Variable was created at:
 em_fxsave+0xcb/0x850 arch/x86/kvm/emulate.c:4060
 x86_emulate_insn+0x24c5/0xa660 arch/x86/kvm/emulate.c:5601

Bytes 8-127 of 128 are uninitialized
Memory access of size 128 starts at ffff88810394ed80
Data copied to user address 0000000020001f80
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