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KCSAN: data-race in kvm_mmu_notifier_change_pte / tdp_page_fault

Status: closed as invalid on 2019/11/19 13:44
Subsystems: kvm
[Documentation on labels]
First crash: 1634d, last: 1634d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in kvm_mmu_notifier_change_pte / tdp_page_fault (2) kvm 2 1561d 1612d 0/26 auto-closed as invalid on 2020/03/26 12:43

Sample crash report:
==================================================================
BUG: KCSAN: data-race in kvm_mmu_notifier_change_pte / tdp_page_fault

read to 0xffffc90000f95130 of 8 bytes by task 17679 on cpu 1:
 tdp_page_fault+0x1d8/0x4d0 arch/x86/kvm/mmu.c:4200
 kvm_mmu_page_fault+0xf9/0xbc0 arch/x86/kvm/mmu.c:5439
 handle_ept_violation+0x1e5/0x340 arch/x86/kvm/vmx/vmx.c:5185
 vmx_handle_exit+0x1c2/0xd60 arch/x86/kvm/vmx/vmx.c:5929
 vcpu_enter_guest+0xc1f/0x3830 arch/x86/kvm/x86.c:8227
 vcpu_run arch/x86/kvm/x86.c:8291 [inline]
 kvm_arch_vcpu_ioctl_run+0x2a2/0xdc0 arch/x86/kvm/x86.c:8498
 kvm_vcpu_ioctl+0x752/0xa30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2772
 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

write to 0xffffc90000f95130 of 8 bytes by task 17678 on cpu 0:
 kvm_mmu_notifier_change_pte+0x69/0xf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:360
 __mmu_notifier_change_pte+0xb0/0x140 mm/mmu_notifier.c:157
 mmu_notifier_change_pte include/linux/mmu_notifier.h:340 [inline]
 wp_page_copy+0x103c/0x1120 mm/memory.c:2375
 do_wp_page+0x192/0x11f0 mm/memory.c:2628
 handle_pte_fault mm/memory.c:3865 [inline]
 __handle_mm_fault+0x1ab1/0x2c70 mm/memory.c:3973
 handle_mm_fault+0x21b/0x530 mm/memory.c:4010
 do_user_addr_fault arch/x86/mm/fault.c:1441 [inline]
 __do_page_fault+0x3fb/0x9e0 arch/x86/mm/fault.c:1506
 do_page_fault+0x54/0x233 arch/x86/mm/fault.c:1530
 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1202

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17678 Comm: syz-executor.3 Not tainted 5.4.0-rc6+ #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
2019/11/04 17:24 https://github.com/google/ktsan.git kcsan 94c006602e13 18e12644 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.