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KCSAN: data-race in install_new_memslots / mark_mmio_spte

Status: closed as invalid on 2019/11/19 13:44
Subsystems: kvm
[Documentation on labels]
First crash: 1923d, last: 1923d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in install_new_memslots / mark_mmio_spte

write to 0xffff8880bba20000 of 8 bytes by task 13672 on cpu 0:
 install_new_memslots+0xef/0x130 arch/x86/kvm/../../../virt/kvm/kvm_main.c:906
 __kvm_set_memory_region+0xeea/0x1380 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1065
 kvm_set_memory_region+0x36/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1088
 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1100 [inline]
 kvm_vm_ioctl+0x6d0/0x1190 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3224
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x991/0xc60 fs/ioctl.c:696
 ksys_ioctl+0xbd/0xe0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x4c/0x60 fs/ioctl.c:718
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880bba20000 of 8 bytes by task 13670 on cpu 1:
 mark_mmio_spte+0x9a/0x250 arch/x86/kvm/mmu.c:422
 set_mmio_spte arch/x86/kvm/mmu.c:455 [inline]
 set_spte+0x7a4/0x8b0 arch/x86/kvm/mmu.c:2997
 mmu_set_spte+0xbd/0x790 arch/x86/kvm/mmu.c:3122
 __direct_map+0x2f8/0x570 arch/x86/kvm/mmu.c:3264
 tdp_page_fault+0x462/0x4d0 arch/x86/kvm/mmu.c:4217
 kvm_mmu_page_fault+0xf9/0xbc0 arch/x86/kvm/mmu.c:5439
 handle_ept_misconfig+0xbf/0x1f0 arch/x86/kvm/vmx/vmx.c:5211
 vmx_handle_exit+0x1c2/0xd60 arch/x86/kvm/vmx/vmx.c:5949
 vcpu_enter_guest+0xc1f/0x3820 arch/x86/kvm/x86.c:8226
 vcpu_run arch/x86/kvm/x86.c:8290 [inline]
 kvm_arch_vcpu_ioctl_run+0x2a2/0xdc0 arch/x86/kvm/x86.c:8497
 kvm_vcpu_ioctl+0x752/0xa30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2765
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x991/0xc60 fs/ioctl.c:696
 ksys_ioctl+0xbd/0xe0 fs/ioctl.c:713

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13670 Comm: syz-executor.3 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/24 08:30 https://github.com/google/ktsan.git kcsan 05f2236801fe d01bb02a .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.