syzbot


KCSAN: data-race in direct_page_fault / kvm_set_memslot (2)

Status: auto-closed as invalid on 2021/01/09 08:12
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+bd01b6d8ba4d4d5ec9e2@syzkaller.appspotmail.com
First crash: 1270d, last: 1230d
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 kvm 3 1306d 1351d 0/26 auto-closed as invalid on 2020/10/25 17:28

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

write to 0xffff88801416e000 of 8 bytes by task 22474 on cpu 0:
 install_new_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:1146 [inline]
 kvm_set_memslot+0x945/0xa00 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1222
 __kvm_set_memory_region+0x708/0x910 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1374
 kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1395 [inline]
 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1407 [inline]
 kvm_vm_ioctl+0x822/0x17d0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3708
 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 0xffff88801416e000 of 8 bytes by task 22438 on cpu 1:
 vcpu_cache_mmio_info arch/x86/kvm/x86.h:172 [inline]
 handle_abnormal_pfn arch/x86/kvm/mmu/mmu.c:2952 [inline]
 direct_page_fault+0x491/0x770 arch/x86/kvm/mmu/mmu.c:3708
 kvm_tdp_page_fault+0x92/0xa0 arch/x86/kvm/mmu/mmu.c:3790
 kvm_mmu_do_page_fault arch/x86/kvm/mmu.h:112 [inline]
 kvm_mmu_page_fault+0xca/0x3c0 arch/x86/kvm/mmu/mmu.c:5059
 handle_ept_misconfig+0x96/0x150 arch/x86/kvm/vmx/vmx.c:5375
 vmx_handle_exit+0x2fd/0x7e0 arch/x86/kvm/vmx/vmx.c:6068
 vcpu_enter_guest+0x199b/0x23b0 arch/x86/kvm/x86.c:9027
 vcpu_run+0x24e/0x690 arch/x86/kvm/x86.c:9092
 kvm_arch_vcpu_ioctl_run+0x362/0x660 arch/x86/kvm/x86.c:9309
 kvm_vcpu_ioctl+0x562/0x8f0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3234
 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: 1 PID: 22438 Comm: syz-executor.5 Not tainted 5.10.0-rc6-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
2020/12/05 08:11 upstream b3298500b23f 0ef84591 .config console log report info ci2-upstream-kcsan-gce
2020/11/28 03:20 upstream c84e1efae022 486f93ef .config console log report info ci2-upstream-kcsan-gce
2020/10/26 05:34 upstream 986b9eacb259 a1839e81 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.