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KCSAN: data-race in direct_page_fault / kvm_set_memslot

Status: auto-closed as invalid on 2020/10/25 17:28
Subsystems: kvm
[Documentation on labels]
First crash: 1358d, last: 1313d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in direct_page_fault / kvm_set_memslot (2) kvm 3 1238d 1235d 0/26 auto-closed as invalid on 2021/01/09 08:12

Sample crash report:
==================================================================
BUG: KCSAN: data-race in direct_page_fault / kvm_set_memslot

write to 0xffff88802fdb1000 of 8 bytes by task 12483 on cpu 1:
 install_new_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:1148 [inline]
 kvm_set_memslot+0x866/0x910 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1224
 __kvm_set_memory_region+0x708/0x910 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1370
 kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1391 [inline]
 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1403 [inline]
 kvm_vm_ioctl+0x81d/0x17c0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3704
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88802fdb1000 of 8 bytes by task 12465 on cpu 0:
 vcpu_cache_mmio_info arch/x86/kvm/x86.h:172 [inline]
 handle_abnormal_pfn arch/x86/kvm/mmu/mmu.c:3391 [inline]
 direct_page_fault+0x44c/0x740 arch/x86/kvm/mmu/mmu.c:4111
 kvm_tdp_page_fault+0x92/0xa0 arch/x86/kvm/mmu/mmu.c:4188
 kvm_mmu_do_page_fault arch/x86/kvm/mmu.h:112 [inline]
 kvm_mmu_page_fault+0xca/0x410 arch/x86/kvm/mmu/mmu.c:5451
 handle_ept_misconfig+0x99/0x230 arch/x86/kvm/vmx/vmx.c:5355
 vmx_handle_exit+0x558/0xc30 arch/x86/kvm/vmx/vmx.c:6119
 vcpu_enter_guest+0x1ada/0x2660 arch/x86/kvm/x86.c:8641
 vcpu_run+0x26e/0x740 arch/x86/kvm/x86.c:8706
 kvm_arch_vcpu_ioctl_run+0x38d/0x6a0 arch/x86/kvm/x86.c:8923
 kvm_vcpu_ioctl+0x565/0x950 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3230
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12465 Comm: syz-executor.4 Not tainted 5.9.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/09/20 17:26 upstream 325d0eab4f31 9564d2e9 .config console log report info ci2-upstream-kcsan-gce
2020/08/20 04:39 upstream 18445bf405cb ed282a3a .config console log report ci2-upstream-kcsan-gce
2020/08/06 16:30 upstream 47ec5303d73e 4ca1c0ea .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.