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KCSAN: data-race in kvm_set_memslot / vcpu_mmio_gva_to_gpa (3)

Status: auto-closed as invalid on 2020/12/21 11:51
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+c6da4365afd3f07abdc3@syzkaller.appspotmail.com
First crash: 1281d, last: 1254d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in kvm_set_memslot / vcpu_mmio_gva_to_gpa (2) kvm 1 1352d 1352d 0/26 auto-closed as invalid on 2020/09/06 22:08
upstream KCSAN: data-race in kvm_set_memslot / vcpu_mmio_gva_to_gpa kvm 1 1396d 1396d 0/26 auto-closed as invalid on 2020/07/25 12:23
upstream KCSAN: data-race in kvm_set_memslot / vcpu_mmio_gva_to_gpa (4) kvm 1 1170d 1170d 0/26 auto-closed as invalid on 2021/03/08 13:59

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

write to 0xffff888024d55000 of 8 bytes by task 6237 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 0xffff888024d55000 of 8 bytes by task 6221 on cpu 1:
 vcpu_match_mmio_gen arch/x86/kvm/x86.h:189 [inline]
 vcpu_match_mmio_gpa arch/x86/kvm/x86.h:217 [inline]
 vcpu_is_mmio_gpa arch/x86/kvm/x86.c:6038 [inline]
 vcpu_mmio_gva_to_gpa+0x2c8/0x540 arch/x86/kvm/x86.c:6072
 emulator_read_write_onepage+0xfd/0x490 arch/x86/kvm/x86.c:6183
 emulator_read_write+0x173/0x310 arch/x86/kvm/x86.c:6243
 emulator_read_emulated+0x37/0x40 arch/x86/kvm/x86.c:6270
 read_emulated arch/x86/kvm/emulate.c:1457 [inline]
 segmented_read arch/x86/kvm/emulate.c:1481 [inline]
 emulate_pop+0x214/0x410 arch/x86/kvm/emulate.c:1909
 em_ret_far+0x9d/0x2b0 arch/x86/kvm/emulate.c:2311
 em_ret_far_imm+0x2c/0x1c0 arch/x86/kvm/emulate.c:2334
 x86_emulate_insn+0x9d9/0x3060 arch/x86/kvm/emulate.c:5702
 x86_emulate_instruction+0x74f/0x2ac0 arch/x86/kvm/x86.c:7350
 kvm_mmu_page_fault+0x315/0x3c0 arch/x86/kvm/mmu/mmu.c:5095
 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+0x1978/0x2390 arch/x86/kvm/x86.c:8987
 vcpu_run+0x26e/0x730 arch/x86/kvm/x86.c:9052
 kvm_arch_vcpu_ioctl_run+0x362/0x660 arch/x86/kvm/x86.c:9269
 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: 6221 Comm: syz-executor.1 Not tainted 5.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/11/08 20:09 upstream 9dbc1c03eeb5 cba33199 .config console log report info ci2-upstream-kcsan-gce
2020/10/12 18:37 upstream bbf5c979011a d32b0bbf .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.