diff mbox

fix memory leak on kvm_vm_ioctl_create_spapr_tce

Message ID 20170822142823.69425-1-nixiaoming@huawei.com
State Superseded
Headers show

Commit Message

Xiaoming Ni Aug. 22, 2017, 2:28 p.m. UTC
miss kfree(stt) when anon_inode_getfd return fail
so add check anon_inode_getfd return val, and kfree stt

Signed-off-by: nixiaoming <nixiaoming@huawei.com>
---
 arch/powerpc/kvm/book3s_64_vio.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

David Hildenbrand Aug. 22, 2017, 3:15 p.m. UTC | #1
On 22.08.2017 16:28, nixiaoming wrote:
> miss kfree(stt) when anon_inode_getfd return fail
> so add check anon_inode_getfd return val, and kfree stt
> 
> Signed-off-by: nixiaoming <nixiaoming@huawei.com>
> ---
>  arch/powerpc/kvm/book3s_64_vio.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
> index a160c14..a0b4459 100644
> --- a/arch/powerpc/kvm/book3s_64_vio.c
> +++ b/arch/powerpc/kvm/book3s_64_vio.c
> @@ -341,8 +341,11 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
>  
>  	mutex_unlock(&kvm->lock);
>  
> -	return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
> +	ret = anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
>  				stt, O_RDWR | O_CLOEXEC);
> +	if (ret < 0)
> +		goto fail;
> +	return ret;
>  
>  fail:
>  	if (stt) {
> 


stt has already been added to kvm->arch.spapr_tce_tables, so freeing it
is evil IMHO. I don't know that code, so I don't know if there is some
other place that will make sure that everything in
kvm->arch.spapr_tce_tables will properly get freed, even when no release
function has been called (kvm_spapr_tce_release).
David Hildenbrand Aug. 22, 2017, 3:23 p.m. UTC | #2
On 22.08.2017 17:15, David Hildenbrand wrote:
> On 22.08.2017 16:28, nixiaoming wrote:
>> miss kfree(stt) when anon_inode_getfd return fail
>> so add check anon_inode_getfd return val, and kfree stt
>>
>> Signed-off-by: nixiaoming <nixiaoming@huawei.com>
>> ---
>>  arch/powerpc/kvm/book3s_64_vio.c | 5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
>> index a160c14..a0b4459 100644
>> --- a/arch/powerpc/kvm/book3s_64_vio.c
>> +++ b/arch/powerpc/kvm/book3s_64_vio.c
>> @@ -341,8 +341,11 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
>>  
>>  	mutex_unlock(&kvm->lock);
>>  
>> -	return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
>> +	ret = anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
>>  				stt, O_RDWR | O_CLOEXEC);
>> +	if (ret < 0)
>> +		goto fail;
>> +	return ret;
>>  
>>  fail:
>>  	if (stt) {
>>
> 
> 
> stt has already been added to kvm->arch.spapr_tce_tables, so freeing it
> is evil IMHO. I don't know that code, so I don't know if there is some
> other place that will make sure that everything in
> kvm->arch.spapr_tce_tables will properly get freed, even when no release
> function has been called (kvm_spapr_tce_release).
> 

If it is really not freed, than also kvm_put_kvm(stt->kvm) is missing.
diff mbox

Patch

diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
index a160c14..a0b4459 100644
--- a/arch/powerpc/kvm/book3s_64_vio.c
+++ b/arch/powerpc/kvm/book3s_64_vio.c
@@ -341,8 +341,11 @@  long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 
 	mutex_unlock(&kvm->lock);
 
-	return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
+	ret = anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
 				stt, O_RDWR | O_CLOEXEC);
+	if (ret < 0)
+		goto fail;
+	return ret;
 
 fail:
 	if (stt) {