From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> stable inclusion from stable-v5.10.169 commit 6416c2108ba54d569e4c98d3b62ac78cb12e7107 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I6OOP3 CVE: CVE-2023-1513 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 2c10b61421a28e95a46ab489fd56c0f442ff6952 upstream. When calling the KVM_GET_DEBUGREGS ioctl, on some configurations, there might be some unitialized portions of the kvm_debugregs structure that could be copied to userspace. Prevent this as is done in the other kvm ioctls, by setting the whole structure to 0 before copying anything into it. Bonus is that this reduces the lines of code as the explicit flag setting and reserved space zeroing out can be removed. Cc: Sean Christopherson <seanjc@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: <x86@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: stable <stable@kernel.org> Reported-by: Xingyuan Mo <hdthky0@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Message-Id: <20230214103304.3689213-1-gregkh@linuxfoundation.org> Tested-by: Xingyuan Mo <hdthky0@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Guo Mengqi <guomengqi3@huawei.com> Reviewed-by: Wang Weiyang <wangweiyang2@huawei.com> Reviewed-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com> --- arch/x86/kvm/x86.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 53ef53d5b414..b2ce17f29c75 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4692,12 +4692,11 @@ static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu, { unsigned long val; + memset(dbgregs, 0, sizeof(*dbgregs)); memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db)); kvm_get_dr(vcpu, 6, &val); dbgregs->dr6 = val; dbgregs->dr7 = vcpu->arch.dr7; - dbgregs->flags = 0; - memset(&dbgregs->reserved, 0, sizeof(dbgregs->reserved)); } static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu, -- 2.25.1