* Re: [PATCH linux-next] KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
2017-12-21 0:30 ` [PATCH linux-next] KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs() Paolo Bonzini
@ 2017-12-21 1:02 ` Stephen Rothwell
2017-12-21 2:45 ` Lan Tianyu
1 sibling, 0 replies; 4+ messages in thread
From: Stephen Rothwell @ 2017-12-21 1:02 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Eric Biggers, kvm, rkrcmar, tianyu.lan, christoffer.dall, x86,
linux-kernel, syzkaller-bugs, Eric Biggers,
Linux-Next Mailing List
Hi Paolo,
On Thu, 21 Dec 2017 01:30:30 +0100 Paolo Bonzini <pbonzini@redhat•com> wrote:
>
> On 21/12/2017 01:24, Eric Biggers wrote:
> > From: Eric Biggers <ebiggers@google•com>
> >
> > Due to a bad merge resolution between commit f29810335965 ("KVM/x86:
> > Check input paging mode when cs.l is set") and commit b4ef9d4e8cb8
> > ("KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_sregs"),
> > there is a case in kvm_arch_vcpu_ioctl_set_sregs() where vcpu_put() is
> > not called after vcpu_get(). Fix it.
> >
> > Reported-by: syzbot <syzkaller@googlegroups•com>
> > Signed-off-by: Eric Biggers <ebiggers@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 ea3a98196753..f4e8b5089b28 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -7624,7 +7624,7 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
> > goto out;
> >
> > if (kvm_valid_sregs(vcpu, sregs))
> > - return -EINVAL;
> > + goto out;
> >
> > apic_base_msr.data = sregs->apic_base;
> > apic_base_msr.host_initiated = true;
> >
>
> Thanks very much Eric, that was fast! Adding Stephen and the linux-next
> mailing list to Cc. Adding the kvm/master tree has already paid off.
I will apply that as a merge fix patch for the kvm tree merge from
today. Please remember to apply it if/when you merge the master branch
into your linux-next branch or when these trees meet in Linus' tree.
--
Cheers,
Stephen Rothwell
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH linux-next] KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
2017-12-21 0:30 ` [PATCH linux-next] KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs() Paolo Bonzini
2017-12-21 1:02 ` Stephen Rothwell
@ 2017-12-21 2:45 ` Lan Tianyu
2017-12-21 9:07 ` Paolo Bonzini
1 sibling, 1 reply; 4+ messages in thread
From: Lan Tianyu @ 2017-12-21 2:45 UTC (permalink / raw)
To: Paolo Bonzini, Eric Biggers, kvm
Cc: rkrcmar, christoffer.dall, x86, linux-kernel, syzkaller-bugs,
Eric Biggers, Stephen Rothwell, Linux-Next Mailing List
On 2017年12月21日 08:30, Paolo Bonzini wrote:
> On 21/12/2017 01:24, Eric Biggers wrote:
>> From: Eric Biggers <ebiggers@google•com>
>>
>> Due to a bad merge resolution between commit f29810335965 ("KVM/x86:
>> Check input paging mode when cs.l is set") and commit b4ef9d4e8cb8
>> ("KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_sregs"),
>> there is a case in kvm_arch_vcpu_ioctl_set_sregs() where vcpu_put() is
>> not called after vcpu_get(). Fix it.
>>
>> Reported-by: syzbot <syzkaller@googlegroups•com>
>> Signed-off-by: Eric Biggers <ebiggers@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 ea3a98196753..f4e8b5089b28 100644
>> --- a/arch/x86/kvm/x86.c
>> +++ b/arch/x86/kvm/x86.c
>> @@ -7624,7 +7624,7 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
>> goto out;
>>
>> if (kvm_valid_sregs(vcpu, sregs))
>> - return -EINVAL;
>> + goto out;
>>
>> apic_base_msr.data = sregs->apic_base;
>> apic_base_msr.host_initiated = true;
>>
>
> Thanks very much Eric, that was fast! Adding Stephen and the linux-next
> mailing list to Cc. Adding the kvm/master tree has already paid off.
>
> Paolo
>
Hi Paolo:
Should we check input sregs before loading vcpu? If input sregs is
invalid, the operation is redundant.
--
Best regards
Tianyu Lan
^ permalink raw reply [flat|nested] 4+ messages in thread