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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: 10540 Comm: syz-executor5 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+0x5c8/0x600 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1876
 nested_release_vmcs12+0x2e2/0x490 arch/x86/kvm/vmx.c:8489
 handle_vmptrld+0x20e2/0x22f0 arch/x86/kvm/vmx.c:9328
 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:00007f9cac1f1c78 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: 00007f9cac1f26d4
R13: 00000000004c0505 R14: 00000000004d1580 R15: 00000000ffffffff

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:247 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:170
 kmsan_kmalloc+0xa1/0x100 mm/kmsan/kmsan_hooks.c:179
 kmem_cache_alloc_trace+0x56d/0xc30 mm/slub.c:2789
binder: 10557:10558 ioctl c0306201 200001c0 returned -14
 kmalloc include/linux/slab.h:546 [inline]
 enter_vmx_operation+0x104/0x1190 arch/x86/kvm/vmx.c:8315
 vmx_set_nested_state+0xdc9/0x18a0 arch/x86/kvm/vmx.c:14922
 kvm_arch_vcpu_ioctl+0x4a95/0x73a0 arch/x86/kvm/x86.c:4190
 kvm_vcpu_ioctl+0xcde/0x1d80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2748
 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

Bytes 1000-4095 of 4096 are uninitialized
Memory access of size 4096 starts at ffff888135c07000
Data copied to user address 0000000020feb000
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