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From:   Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
To:     Jason Gunthorpe <jgg@nvidia.com>,
        Alex Williamson <alex.williamson@redhat.com>
CC:     liulongfang <liulongfang@huawei.com>,
        "cohuck@redhat.com" <cohuck@redhat.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linuxarm@openeuler.org" <linuxarm@openeuler.org>
Subject: RE: [PATCH 1/5] hisi_acc_vfio_pci: Fixes a memory leak bug
Thread-Topic: [PATCH 1/5] hisi_acc_vfio_pci: Fixes a memory leak bug
Thread-Index: AQHYyKNl0n81Lxv0MUKz8I4GKo4bYq3oe7uAgAABAQCAABOTkA==
Date:   Tue, 20 Sep 2022 17:03:34 +0000
Message-ID: <04a17bfa71c440e8a38cba2337a8c6ac@huawei.com>
References: <20220915013157.60771-1-liulongfang@huawei.com>
 <20220915013157.60771-2-liulongfang@huawei.com>
 <20220920103443.72654dd7.alex.williamson@redhat.com>
 <YynsesGyvJl26jDI@nvidia.com>
In-Reply-To: <YynsesGyvJl26jDI@nvidia.com>
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> -----Original Message-----
> From: Jason Gunthorpe [mailto:jgg@nvidia.com]
> Sent: 20 September 2022 17:38
> To: Alex Williamson <alex.williamson@redhat.com>
> Cc: liulongfang <liulongfang@huawei.com>; Shameerali Kolothum Thodi
> <shameerali.kolothum.thodi@huawei.com>; cohuck@redhat.com;
> linux-kernel@vger.kernel.org; linuxarm@openeuler.org
> Subject: Re: [PATCH 1/5] hisi_acc_vfio_pci: Fixes a memory leak bug
> 
> On Tue, Sep 20, 2022 at 10:34:43AM -0600, Alex Williamson wrote:
> > On Thu, 15 Sep 2022 09:31:53 +0800
> > Longfang Liu <liulongfang@huawei.com> wrote:
> >
> > > During the stop copy phase of live migration, the driver allocates a
> > > memory for the migrated data to save the data.
> > >
> > > When an exception occurs when the driver reads device data, the
> > > driver will report an error to qemu and exit the current migration state.
> > > But this memory is not released, which will lead to a memory leak
> > > problem.
> 
> Why isn't it released? The fput() releases it:
> 
> static int hisi_acc_vf_release_file(struct inode *inode, struct file *filp) {
> 	struct hisi_acc_vf_migration_file *migf = filp->private_data;
> 
> 	hisi_acc_vf_disable_fd(migf);
> 	mutex_destroy(&migf->lock);
> 	kfree(migf);
>         ^^^^^^^^^^
> 
> This patch looks wrong to me.

That's right. Missed that. Sorry of the oversight.

Thanks,
Shameer