* [PATCH for-4,5] mips/kvm: fix ioctl error handling
@ 2016-02-28 15:35 Michael S. Tsirkin
2016-02-28 17:35 ` Sergei Shtylyov
2016-03-02 9:35 ` Paolo Bonzini
0 siblings, 2 replies; 3+ messages in thread
From: Michael S. Tsirkin @ 2016-02-28 15:35 UTC (permalink / raw)
To: linux-kernel
Cc: stable, Paolo Bonzini, James Hogan, Ralf Baechle, kvm, linux-mips
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 <mst@redhat.com>
---
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;
}
--
MST
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH for-4,5] mips/kvm: fix ioctl error handling
2016-02-28 15:35 [PATCH for-4,5] mips/kvm: fix ioctl error handling Michael S. Tsirkin
@ 2016-02-28 17:35 ` Sergei Shtylyov
2016-03-02 9:35 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Sergei Shtylyov @ 2016-02-28 17:35 UTC (permalink / raw)
To: Michael S. Tsirkin, linux-kernel
Cc: stable, Paolo Bonzini, James Hogan, Ralf Baechle, kvm, linux-mips
Hello.
On 02/28/2016 06:35 PM, Michael S. Tsirkin wrote:
> Calling return copy_to_user(...) or return copy_from_user in an ioctl
Calling return? Perhaps "returning the result of"?
> 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 <mst@redhat.com>
[...]
MBR, Sergei
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH for-4,5] mips/kvm: fix ioctl error handling
2016-02-28 15:35 [PATCH for-4,5] mips/kvm: fix ioctl error handling Michael S. Tsirkin
2016-02-28 17:35 ` Sergei Shtylyov
@ 2016-03-02 9:35 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2016-03-02 9:35 UTC (permalink / raw)
To: Michael S. Tsirkin, linux-kernel
Cc: stable, James Hogan, Ralf Baechle, kvm, linux-mips
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 <mst@redhat.com>
> ---
>
> 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
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-02-28 15:35 [PATCH for-4,5] mips/kvm: fix ioctl error handling Michael S. Tsirkin
2016-02-28 17:35 ` Sergei Shtylyov
2016-03-02 9:35 ` Paolo Bonzini
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