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KCSAN: data-race in kvm_set_memslot / kvm_write_guest_offset_cached

Status: auto-closed as invalid on 2021/03/17 08:58
Subsystems: kvm
[Documentation on labels]
First crash: 1163d, last: 1163d

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

write to 0xffff888135c65000 of 8 bytes by task 21973 on cpu 1:
 install_new_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:1148 [inline]
 kvm_set_memslot+0x958/0xa10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1224
 __kvm_set_memory_region+0x794/0x930 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1377
 kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1398 [inline]
 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1410 [inline]
 kvm_vm_ioctl+0xacb/0x1c40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3825
 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 0xffff888135c65000 of 8 bytes by task 21963 on cpu 0:
 kvm_write_guest_offset_cached+0x85/0x360 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2573
 kvm_write_guest_cached+0x2b/0x40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2596
 kvm_setup_pvclock_page+0xbf/0x280 arch/x86/kvm/x86.c:2623
 kvm_guest_time_update arch/x86/kvm/x86.c:2735 [inline]
 vcpu_enter_guest+0x870/0x2470 arch/x86/kvm/x86.c:8831
 vcpu_run+0x24e/0x690 arch/x86/kvm/x86.c:9155
 kvm_arch_vcpu_ioctl_run+0x466/0x850 arch/x86/kvm/x86.c:9382
 kvm_vcpu_ioctl+0x562/0x8f0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3283
 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: 21963 Comm: syz-executor.1 Not tainted 5.11.0-rc7-syzkaller #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
2021/02/10 08:58 upstream e0756cfc7d7c 9c8b8541 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in kvm_set_memslot / kvm_write_guest_offset_cached
* Struck through repros no longer work on HEAD.