usercopy: kernel memory overwrite attempt detected to 000000000ff77c39 (kmalloc-1024) (1024 bytes) ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:84! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 13937 Comm: syz-executor3 Not tainted 4.15.0-rc4-mm1+ #49 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:report_usercopy mm/usercopy.c:76 [inline] RIP: 0010:__check_object_size+0x3a2/0x4f0 mm/usercopy.c:276 RSP: 0018:ffff8801c075f158 EFLAGS: 00010286 RAX: 0000000000000062 RBX: ffffffff859297a0 RCX: 0000000000000000 RDX: 0000000000000062 RSI: ffffc9000301d000 RDI: ffffed00380ebe1f RBP: ffff8801c075f248 R08: 1ffff100380ebdad R09: 0000000000000000 R10: 000000005b9483b7 R11: 0000000000000000 R12: ffffffff85929760 R13: ffff8801d800d710 R14: 0000000000000400 R15: ffffea0007600300 FS: 00007f6d804c8700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000071c000 CR3: 00000001bfc1f002 CR4: 00000000001626e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_object_size include/linux/thread_info.h:112 [inline] check_copy_size include/linux/thread_info.h:143 [inline] copy_from_user include/linux/uaccess.h:146 [inline] memdup_user+0x46/0x90 mm/util.c:168 kvm_arch_vcpu_ioctl+0x1984/0x4760 arch/x86/kvm/x86.c:3550 kvm_vcpu_ioctl+0x244/0xff0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2707 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452ac9 RSP: 002b:00007f6d804c7c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9 RDX: 0000000020390c00 RSI: 000000004400ae8f RDI: 0000000000000016 RBP: 00000000000003a3 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f37e8 R13: 00000000ffffffff R14: 00007f6d804c86d4 R15: 0000000000000000 Code: 48 0f 44 da e8 80 76 c1 ff 48 8b 85 28 ff ff ff 4d 89 f1 4c 89 e9 4c 89 e2 48 89 de 48 c7 c7 60 98 92 85 49 89 c0 e8 86 2f ab ff <0f> 0b 48 c7 c0 20 96 92 85 eb 96 48 c7 c0 60 96 92 85 eb 8d 48 RIP: report_usercopy mm/usercopy.c:76 [inline] RSP: ffff8801c075f158 RIP: __check_object_size+0x3a2/0x4f0 mm/usercopy.c:276 RSP: ffff8801c075f158 ---[ end trace c523fc227a5ed81a ]--- Kernel panic - not syncing: Fatal exception Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..