From: Wanpeng Li wanpengli@tencent.com
mainline inclusion from mainline-v5.17-rc2 commit 35fe7cfbab2e81f1afb23fc4212210b1de6d9633 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA72K9 CVE: CVE-2022-48765
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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The below warning is splatting during guest reboot.
------------[ cut here ]------------ WARNING: CPU: 0 PID: 1931 at arch/x86/kvm/x86.c:10322 kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm] CPU: 0 PID: 1931 Comm: qemu-system-x86 Tainted: G I 5.17.0-rc1+ #5 RIP: 0010:kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm] Call Trace: <TASK> kvm_vcpu_ioctl+0x279/0x710 [kvm] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fd39797350b
This can be triggered by not exposing tsc-deadline mode and doing a reboot in the guest. The lapic_shutdown() function which is called in sys_reboot path will not disarm the flying timer, it just masks LVTT. lapic_shutdown() clears APIC state w/ LVT_MASKED and timer-mode bit is 0, this can trigger timer-mode switch between tsc-deadline and oneshot/periodic, which can result in preemption timer be cancelled in apic_update_lvtt(). However, We can't depend on this when not exposing tsc-deadline mode and oneshot/periodic modes emulated by preemption timer. Qemu will synchronise states around reset, let's cancel preemption timer under KVM_SET_LAPIC.
Signed-off-by: Wanpeng Li wanpengli@tencent.com Message-Id: 1643102220-35667-1-git-send-email-wanpengli@tencent.com Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Zeng Heng zengheng4@huawei.com --- arch/x86/kvm/lapic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 610a79f1c469..d6272f97368f 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2631,7 +2631,7 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) kvm_apic_set_version(vcpu);
apic_update_ppr(apic); - hrtimer_cancel(&apic->lapic_timer.timer); + cancel_apic_timer(apic); apic_update_lvtt(apic); apic_manage_nmi_watchdog(apic, kvm_lapic_get_reg(apic, APIC_LVT0)); update_divide_count(apic);