From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH for-4,5] mips/kvm: fix ioctl error handling To: "Michael S. Tsirkin" , linux-kernel@vger.kernel.org References: <1456673711-24132-1-git-send-email-mst@redhat.com> Cc: stable@vger.kernel.org, James Hogan , Ralf Baechle , kvm@vger.kernel.org, linux-mips@linux-mips.org From: Paolo Bonzini Message-ID: <56D6B3D8.1090000@redhat.com> Date: Wed, 2 Mar 2016 10:35:20 +0100 MIME-Version: 1.0 In-Reply-To: <1456673711-24132-1-git-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: On 28/02/2016 16:35, Michael S. Tsirkin wrote: > Calling return copy_to_user(...) or return copy_from_user in an ioctl > will not do the right thing if there's a pagefault: > copy_to_user/copy_from_user return the number of bytes not copied in > this case. > > Fix up kvm on mips to do > return copy_to_user(...)) ? -EFAULT : 0; > and > return copy_from_user(...)) ? -EFAULT : 0; > > everywhere. > > Cc: stable@vger.kernel.org > Signed-off-by: Michael S. Tsirkin > --- > > Untested. > > arch/mips/kvm/mips.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c > index 8bc3977..3110447 100644 > --- a/arch/mips/kvm/mips.c > +++ b/arch/mips/kvm/mips.c > @@ -702,7 +702,7 @@ static int kvm_mips_get_reg(struct kvm_vcpu *vcpu, > } else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) { > void __user *uaddr = (void __user *)(long)reg->addr; > > - return copy_to_user(uaddr, vs, 16); > + return copy_to_user(uaddr, vs, 16) ? -EFAULT : 0; > } else { > return -EINVAL; > } > @@ -732,7 +732,7 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu, > } else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) { > void __user *uaddr = (void __user *)(long)reg->addr; > > - return copy_from_user(vs, uaddr, 16); > + return copy_from_user(vs, uaddr, 16) ? -EFAULT : 0; > } else { > return -EINVAL; > } > Applied with the commit message tweak suggested by Sergei. Paolo