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From:   Trond Myklebust <trondmy@hammerspace.com>
To:     Benjamin Coddington <bcodding@redhat.com>
CC:     Konstantin Meskhidze <konstantin.meskhidze@huawei.com>,
        Trond Myklebust <trondmy@hammerspace.com>,
        "anna@kernel.org" <anna@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
        "yusongping@huawei.com" <yusongping@huawei.com>,
        "hukeping@huawei.com" <hukeping@huawei.com>,
        "artem.kuzin@huawei.com" <artem.kuzin@huawei.com>
Subject: Re: [PATCH] NFSv4.1: Fix memory leakage
Thread-Topic: [PATCH] NFSv4.1: Fix memory leakage
Thread-Index: AQHZC8nZC2iXpfIn9E+pr8pqvDIwIa5lpEIA
Date:   Fri, 9 Dec 2022 14:53:05 +0000
Message-ID: <1B4CB75E-5227-4B07-A390-175024B3219E@hammerspace.com>
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> On Dec 9, 2022, at 07:29, Benjamin Coddington <bcodding@redhat.com> wrote=
:
>=20
> On 8 Dec 2022, at 21:18, Konstantin Meskhidze wrote:
>=20
>> This commit fixes potential memory leakage of 'calldata' memory chunk
>> in _nfs41_proc_sequence() function.
>>=20
>> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
>> ---
>> fs/nfs/nfs4proc.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>=20
>> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
>> index 86ed5c0142c3..b7aa66167341 100644
>> --- a/fs/nfs/nfs4proc.c
>> +++ b/fs/nfs/nfs4proc.c
>> @@ -9416,8 +9416,10 @@ static struct rpc_task *_nfs41_proc_sequence(stru=
ct nfs_client *clp,
>> task_setup_data.callback_data =3D calldata;
>>=20
>> ret =3D rpc_run_task(&task_setup_data);
>> - if (IS_ERR(ret))
>> + if (IS_ERR(ret)) {
>> + kfree(calldata);
>> goto out_err;
>> + }
>> return ret;
>> out_put_clp:
>> nfs_put_client(clp);
>> --=20
>> 2.25.1
>=20
> Did you observe this leak, or find it by code inspecton?
>=20
> I don't think there's a leak here because there's no way rpc_run_task() c=
an
> return an error withouth also doing rpc_call_ops->rpc_release, which shou=
ld
> free the calldata.

Correct. We will not be applying this patch.
_________________________________
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com