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BUG: KASAN: null-ptr-deref in memset include/linux/string.h:332 [inline]
BUG: KASAN: null-ptr-deref in kvm_write_guest_virt_system+0x64/0x90 arch/x86/kvm/x86.c:4730
Write of size 24 at addr           (null) by task syz-executor.2/27461

CPU: 0 PID: 27461 Comm: syz-executor.2 Not tainted 4.14.146 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x197 lib/dump_stack.c:53
 kasan_report_error mm/kasan/report.c:349 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0x127/0x2af mm/kasan/report.c:393
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x123/0x190 mm/kasan/kasan.c:267
 memset+0x24/0x40 mm/kasan/kasan.c:285
 memset include/linux/string.h:332 [inline]
 kvm_write_guest_virt_system+0x64/0x90 arch/x86/kvm/x86.c:4730
 handle_vmread+0x548/0x730 arch/x86/kvm/vmx.c:8027
 vmx_handle_exit+0x20d/0x1330 arch/x86/kvm/vmx.c:9203
 vcpu_enter_guest+0xf28/0x5210 arch/x86/kvm/x86.c:7247
 vcpu_run arch/x86/kvm/x86.c:7310 [inline]
 kvm_arch_vcpu_ioctl_run+0x318/0x1000 arch/x86/kvm/x86.c:7477
 kvm_vcpu_ioctl+0x401/0xd10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2611
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459a29
RSP: 002b:00007f2707c8cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a29
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2707c8d6d4
R13: 00000000004c2ddb R14: 00000000004d6618 R15: 00000000ffffffff
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