Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Chuck Lever III <chuck.lever@oracle.com>
To:     Azeem Shaikh <azeemshaikh38@gmail.com>
CC:     Jeff Layton <jlayton@kernel.org>,
        "linux-hardening@vger.kernel.org" <linux-hardening@vger.kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] NFSD: Remove all occurences of strlcpy
Thread-Topic: [PATCH v2] NFSD: Remove all occurences of strlcpy
Thread-Index: AQHZhOJYGV62rs3GkUCJMHqFG7AZcq9WvaEAgAAnyoCAADM6AIAAYPYA
Date:   Sat, 13 May 2023 02:22:06 +0000
Message-ID: <A1414FC8-9CE0-4B8C-ABB1-2365E2F62B10@oracle.com>
References: <20230512145356.396567-1-azeemshaikh38@gmail.com>
 <109A2974-3AE0-48C6-8EE3-FADE95E8EF30@oracle.com>
 <5E054593-8995-46FF-824E-55B18BF53BE2@oracle.com>
 <CADmuW3UQ-wqobay34PY+myyk1Pr7s-cf7b-U7TUCnarEf+jsxg@mail.gmail.com>
In-Reply-To: <CADmuW3UQ-wqobay34PY+myyk1Pr7s-cf7b-U7TUCnarEf+jsxg@mail.gmail.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?KUQ8/0qBBL3eysaAII/z5MfUnKswmztCbeSaN7V0FijlfNIl+bFgSwb60559?=
 =?us-ascii?Q?/AAgoAtIrBL3WmhOOJTe4FegGZiI3y5shiMRvm5lcBp3+sBH5YG5pDsRYnQX?=
 =?us-ascii?Q?lItR7aAECFS9LNr/XPZB7XrF7KFeRazthaYacyCZSbjCfj3AkqT113qkRWtP?=
 =?us-ascii?Q?iDRS0071uM2utdj2+ULZyuCIqk/34CqrRrPDUxnSWgPK2dk46LnSVMQOJ7zr?=
 =?us-ascii?Q?vI/zBdUiIWfdsSenhTJ+EtTPIkJgiWuhb4/s9l6fwvpIX9780w7wmZ/x1su6?=
 =?us-ascii?Q?SsTkqUuntl0cE9a023hjHnjYzGdWBBs0UHX2wpTNxdmasthZLkw/4b4tSXXB?=
 =?us-ascii?Q?gln6eBf02n+0/d2AyADlrjJuz6La3/3yrzP2mYhoZHSMCBZ4dbVt8ccJcXjo?=
 =?us-ascii?Q?covSnKguGFWXYX/IkYlOddFbeqFyczWsaeKDRwgZGnyDa0qHElcRb01wdW8+?=
 =?us-ascii?Q?m5t3hk16umllGepvg0gX17o0mUNRWU64q8WVHA5odoO/jRYHN/2giNJJMJXq?=
 =?us-ascii?Q?xJMxWgGDiT9LJA+QJh0+9l0Ie8P5A55If3xTpLsgAa2my1N2rnR+UdynKogS?=
 =?us-ascii?Q?l3XgYS3ceJcWWmAM5rsxeLGdhki+0c2b/if22WF4cRR9CchsPSb3n0CY1Bmp?=
 =?us-ascii?Q?+Vv2w2tDck1ZGO8aKRA1qwezUgzNP92jBSBnrviS4qZFYn4ONKFR2C+xYE8e?=
 =?us-ascii?Q?Mz+gPElRlumL2T6j2lmyBK8qeAvLea8E5SXq1SY3OKBCqnNGQPCtI1z72uqt?=
 =?us-ascii?Q?NSxY8bMhXAx0kgH8RUE/RF1At3NTgWnA8GHWjjJIvbkcjhFKvaXtfpsL7c1z?=
 =?us-ascii?Q?EC0pAj8FXqNT2e2+Ozv/0MzlqkKromGAGv0MvRLAeOffifscjHt3JQp66mY9?=
 =?us-ascii?Q?P0O0nK/EofQ2PW+Fs7uU5ULkg7zHlEaXED5aFSQDRazsVXr1EhwBD4yf/vsF?=
 =?us-ascii?Q?CSKYq1FwNxG294PytFFULv68bHNkoRDBuilOdOlhiw5TY3YxCcKOp9fzIHAn?=
 =?us-ascii?Q?4MNl7ue0VLUL4uPUZ2KRH+gii5s8ihM3Zi3Gb6mBiSSL/ldrHS4sK52moMhN?=
 =?us-ascii?Q?ylIwAth3a4RThbnOWnrjXBFUkWaK3wmu6ZpAuXKJmsJSihoDklo+h3YVT/3w?=
 =?us-ascii?Q?V1NGEsHaR9gGUU4AvPuPnIEj5WsPaQ9KQ1z5nDNBGOYAPe8e5Tj38cSHhrAY?=
 =?us-ascii?Q?1vznXKi6uA+KXm9MVAKrfPaXsKUYI+tR09Bky3ukKtT1ynSUFJkZre4TrjA5?=
 =?us-ascii?Q?PBfMAKbikteqcXE7yikHFyK4dZyQMEfRRHgTDFZWzne1FFnBnU9u9jsjET+n?=
 =?us-ascii?Q?plxk/IG9J5Il3kslktZ5Mse6+WAobKdL7movuwnl1uSukOfLhNRToA3sLwco?=
 =?us-ascii?Q?Gh7qJpyZFmIx8TsAZc8qd6gkHoUyNrkU+RrcjQ5S7S7Jh8s1pWXiyRLf4ilc?=
 =?us-ascii?Q?eKPNm8a5lZUPcMmxpopUD12iBNIh6A6bhD3aAzSCYh470ldOXnBZeh5hyHt9?=
 =?us-ascii?Q?McetdHySH9n0lX7ufxtkLcYNLsPapRiW3bD+U1EDvuOHf01FIwMn1V4UmHl9?=
 =?us-ascii?Q?p3MPKze0+XVSTkU795hl0iBoENa0DZGDoIb9i7PRefuZDmB0QTkdEqCwbb+G?=
 =?us-ascii?Q?2g=3D=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-ID: <9E8CB8EBB156DB48BC2C050D7D49A5F9@namprd10.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: BN0PR10MB5128.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 3ab03eb8-e56f-4895-06f5-08db5358d936
X-MS-Exchange-CrossTenant-originalarrivaltime: 13 May 2023 02:22:06.9359
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: Gl24GmmQvyRJ+c2wWhSn/EXVU/RF/OWhcZmkylcZ3hiR2AtcjQyy27bseqgUhr7109oq97w8jtKCZeuQ47QMoA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR10MB5550
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22
 definitions=2023-05-12_16,2023-05-05_01,2023-02-09_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=690 adultscore=0
 malwarescore=0 mlxscore=0 spamscore=0 bulkscore=0 phishscore=0
 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1
 engine=8.12.0-2304280000 definitions=main-2305130019
X-Proofpoint-ORIG-GUID: prYzhowC0LyDXWBGb93mWRuB0lcw1Ivd
X-Proofpoint-GUID: prYzhowC0LyDXWBGb93mWRuB0lcw1Ivd
X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,SPF_HELO_NONE,
        SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no
        version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-nfs.vger.kernel.org>
X-Mailing-List: linux-nfs@vger.kernel.org


> On May 12, 2023, at 1:34 PM, Azeem Shaikh <azeemshaikh38@gmail.com> wrote=
:
>=20
> Resending as plain text.
>=20
>>>> strlcpy() reads the entire source buffer first.
>>>> This read may exceed the destination size limit.
>>>> This is both inefficient and can lead to linear read
>>>> overflows if a source string is not NUL-terminated [1].
>>>> In an effort to remove strlcpy() completely [2], replace
>>>> strlcpy here.
>>>=20
>>> Let's update the patch description. This change is really
>>> a clean up -- it doesn't address the memory issues you
>>> originally described.
>>=20
>> Unless, of course, you intend to apply this patch /after/
>> a patch that fixes __assign_str(). In that case, no change
>> to the patch description is needed.
>=20
> No, I plan to land this patch before attempting to fix __assign_str itsel=
f.
> Let me know if the below description looks good to you and I'll send
> over a v3 patch:
>=20
> [PATCH v3] NFSD: Remove open coding of string copy
>=20
> Instead of open coding a __dynamic_array(), use the __string() and
> __assign_str()
> helper macros that exist for this kind of use case.
>=20
> Part of an effort to remove deprecated strlcpy() [1] completely from the
> kernel[2].
>=20
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcp=
y
> [2] https://github.com/KSPP/linux/issues/89
>=20
> Fixes: 3c92fba557c6 ("NFSD: Enhance the nfsd_cb_setup tracepoint")
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>

This looks good to me. So you'd like me to take this through
the nfsd tree, possibly for 6.4-rc ?


--
Chuck Lever