| Message ID | 20200511225616.19557-1-jmattson@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: Fix off-by-one error in kvm_vcpu_ioctl_x86_setup_mce | expand |
On Mon, May 11, 2020 at 3:56 PM Jim Mattson <jmattson@google.com> wrote: > > Bank_num is a one-based count of banks, not a zero-based index. It > overflows the allocated space only when strictly greater than > KVM_MAX_MCE_BANKS. > > Fixes: a9e38c3e01ad ("KVM: x86: Catch potential overrun in MCE setup") > Signed-off-by: Jue Wang <juew@google.com> > Signed-off-by: Jim Mattson <jmattson@google.com> > Reviewed-by: Peter Shier <pshier@google.com> > --- > arch/x86/kvm/x86.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index d786c7d27ce5..5bf45c9aa8e5 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3751,7 +3751,7 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu, > unsigned bank_num = mcg_cap & 0xff, bank; > > r = -EINVAL; > - if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS) > + if (!bank_num || bank_num > KVM_MAX_MCE_BANKS) > goto out; > if (mcg_cap & ~(kvm_mce_cap_supported | 0xff | 0xff0000)) > goto out; > -- > 2.26.2.645.ge9eca65c58-goog > Ping?
Jim Mattson <jmattson@google.com> writes: > Bank_num is a one-based count of banks, not a zero-based index. It > overflows the allocated space only when strictly greater than > KVM_MAX_MCE_BANKS. > > Fixes: a9e38c3e01ad ("KVM: x86: Catch potential overrun in MCE setup") > Signed-off-by: Jue Wang <juew@google.com> > Signed-off-by: Jim Mattson <jmattson@google.com> > Reviewed-by: Peter Shier <pshier@google.com> > --- > arch/x86/kvm/x86.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index d786c7d27ce5..5bf45c9aa8e5 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3751,7 +3751,7 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu, > unsigned bank_num = mcg_cap & 0xff, bank; /* it would be great to get rid of bare unsigned-s in kvm_vcpu_ioctl_x86_setup_mce/kvm_vcpu_ioctl_x86_set_mce ... */ > > r = -EINVAL; > - if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS) > + if (!bank_num || bank_num > KVM_MAX_MCE_BANKS) > goto out; > if (mcg_cap & ~(kvm_mce_cap_supported | 0xff | 0xff0000)) > goto out; Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
On 12/05/20 00:56, Jim Mattson wrote: > Bank_num is a one-based count of banks, not a zero-based index. It > overflows the allocated space only when strictly greater than > KVM_MAX_MCE_BANKS. > > Fixes: a9e38c3e01ad ("KVM: x86: Catch potential overrun in MCE setup") > Signed-off-by: Jue Wang <juew@google.com> > Signed-off-by: Jim Mattson <jmattson@google.com> > Reviewed-by: Peter Shier <pshier@google.com> > --- > arch/x86/kvm/x86.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index d786c7d27ce5..5bf45c9aa8e5 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3751,7 +3751,7 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu, > unsigned bank_num = mcg_cap & 0xff, bank; > > r = -EINVAL; > - if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS) > + if (!bank_num || bank_num > KVM_MAX_MCE_BANKS) > goto out; > if (mcg_cap & ~(kvm_mce_cap_supported | 0xff | 0xff0000)) > goto out; > Queued, thanks. Paolo
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d786c7d27ce5..5bf45c9aa8e5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3751,7 +3751,7 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu, unsigned bank_num = mcg_cap & 0xff, bank; r = -EINVAL; - if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS) + if (!bank_num || bank_num > KVM_MAX_MCE_BANKS) goto out; if (mcg_cap & ~(kvm_mce_cap_supported | 0xff | 0xff0000)) goto out;
Bank_num is a one-based count of banks, not a zero-based index. It overflows the allocated space only when strictly greater than KVM_MAX_MCE_BANKS. Fixes: a9e38c3e01ad ("KVM: x86: Catch potential overrun in MCE setup") Signed-off-by: Jue Wang <juew@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Peter Shier <pshier@google.com> --- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)