Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Colin Foster <colin.foster@in-advantage.com>
To:     linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Cc:     =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>,
        John Fastabend <john.fastabend@gmail.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Ilias Apalodimas <ilias.apalodimas@linaro.org>,
        Jesper Dangaard Brouer <hawk@kernel.org>
Subject: [net RFC v1 0/1] Fix NULL pointer dereference in page_pool
Date:   Fri, 21 Jan 2022 16:56:43 -0800
Message-Id: <20220122005644.802352-1-colin.foster@in-advantage.com>
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?C0MSiNsITuz7Y0YO7jfZ5P2AMzOhZBwiRhM1gIfceVj+ZXCOMLGwueN3QAYj?=
 =?us-ascii?Q?rJm/hDyH07rFTPzJDCXJw5rJO+ddJtXvDL7/fGTbmGeSAD/+Pf3xKyir0BzM?=
 =?us-ascii?Q?Hqe3QFdDNb20wbJJ6482xoeQZV/Tp8lJvINF28eQE0GwhWlleSIly0tDZhSp?=
 =?us-ascii?Q?4CfC8XH5/3fC5DSgbqTUnGTR+gik+NbfoKU4FkN5C/Kt/TQMcV6XgnpaZV/o?=
 =?us-ascii?Q?mf+KNiLf4cb7122ft/WypKa2JxbpmtJ17FxNKUNsDJ2J3Ds0HaVtLeJzhvpI?=
 =?us-ascii?Q?VnrPpx11ydF/V3a9+18MZqQOG7kBsCywgOA1x2jBYNiHXWff38FxlipNp49/?=
 =?us-ascii?Q?yXYmh4ZNhr4dvw+bCtlbrECFqP5HRl64rBWWcVW7S3+WnfYgEBdQdo4emhIF?=
 =?us-ascii?Q?Syx3g5xTCHpjngvx2/UpisAKC5GAHfcX6/gGx/FOkSLXaht19QNgO20HwGmJ?=
 =?us-ascii?Q?wMgQUURqWGpuDbSsUUpdqgb9vLoSFeaOL7Fo5ZQqIhZ0BdxcCwiLtJ3Xiyhd?=
 =?us-ascii?Q?1BBaOm/MiWHZBqLrMI5NMt3EdfK9w7XJVVzbmW0CyYJFWsKDohWf71DoIkLj?=
 =?us-ascii?Q?uoF4ZpXwuqJoLAe20bOEMnovJ2020bgQNYfPYdeGs+e4lJjYR5mGPAzBfMPx?=
 =?us-ascii?Q?GhjNsFVruMsDxI9i6gxR1Wo69MgEZtLpS5sWTVaN5n2VFTeLuYevjoqHp+mn?=
 =?us-ascii?Q?Rb4xvJZDEFITthAK96Y0vXdCo39WUkFWOFeL2JE8kiTbS+rk7fdpy2rmfZYM?=
 =?us-ascii?Q?4t2pauYZE42yi/lCjyDPSJEiarsV2bf4AQy727KDnjJTZwwrXnDBVlSzJnyf?=
 =?us-ascii?Q?mDllrAsEsawmjDUzVlEh55Gh4f4yeFg8558O0FkwVg+5tw0LXg3xHgVhgGjl?=
 =?us-ascii?Q?UxsUd8HAMo5fesQlAN30e02M5Rv1PrPYjHTRkk/Vm9wfH4KIfd0aIbCTNtoE?=
 =?us-ascii?Q?YoDTek2mIt4pYOI9pc4VQn7V4EPl+zU3/rpCEL7yB7wtJUn78U2TrJn7wp1y?=
 =?us-ascii?Q?v3wE30eJgu33j3sXtncCrXijYJVWVBlE3MVv/zXzGN9sx2BzLyxWdhnq64lE?=
 =?us-ascii?Q?34eGZePG4kERF4RSazLslK8ujGa3fEaPYt5NRO8/jWl4eOLlGP4aB4uSSH5i?=
 =?us-ascii?Q?Hf4a1RFjZp5TW6dixVEBbAfYSwQHplKs3t8WIG5dGCOQFGyEgGENi50Pkb6n?=
 =?us-ascii?Q?vPre9h3No7djRhqNySVrW33hCSDa7RBLvMZwPqNwPLkR90idjSvdauh5HrnB?=
 =?us-ascii?Q?qdL5WffN6VoZds7bp85x0gXm9xbOkM7LM36v3yAw5r7Tpdi//0wcwXcWM5aN?=
 =?us-ascii?Q?uL4Uz9kZAO1kG1RJ22aDfK1Al91/hmh7vdxn2gQMm/ymAsutQLuvP16nmVRD?=
 =?us-ascii?Q?C3rfJrz1iMIowZ/GzJHsSU0OJLV0YwznY1bomnID9CQmpPHUTR1UgRi5fooU?=
 =?us-ascii?Q?1ktlnzrukIXmBkmGkNKQ99dCLvZGrRt7idgiU0/iWy4e6Bec2KcgvLXNUvzi?=
 =?us-ascii?Q?LcGZ7kcDC7EGOJGPG2TXbRppcU/zJ/ycwhgfzvQWcD64aiE15MXRsQfgP4wS?=
 =?us-ascii?Q?9OaPNobalIauPG/8sf9PL8jXziNbXcDFzrD7EeGeihLsnVZxtTdaVJfHwK6J?=
 =?us-ascii?Q?yg31RsnqgZdKaCZKpR6Oc7oxt4FNcyQ9f+v9MFbY1+7qIfuebV3EDhxtQ9sh?=
 =?us-ascii?Q?bAQfxA=3D=3D?=
X-OriginatorOrg: in-advantage.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 30ce11d3-6d89-49b1-c4a6-08d9dd421642
X-MS-Exchange-CrossTenant-AuthSource: MWHPR1001MB2351.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Jan 2022 00:56:56.3971
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 48e842ca-fbd8-4633-a79d-0c955a7d3aae
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: g6bYoowf37FopHv4deTvw1oIBsM/mYblV+kneUnnaA06xzM3Thr1JctU2/P7S7hNwPJBHdmif9pEjnS18AggueAIbIDP+I5CMLghfDTxGwU=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR10MB4022
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

I'm not sure if there's something wrong with my config, but as soon as I
run "ip link set eth0 up" I would get a crash that would invoke a
seemingly endless memory dump.

git bisect led me to the page_pool, where there isn't the existence of
page_pool_params inside of the pool. Therefore the check of
if (pool->p.init_callback) would cause a crash.

I have some out-of-tree patches currently, so I'm not sure if my case is
valid. Specifically the MTU of cpsw_new has been updated to 1520 to
account for my setup (beaglebone with eth0 as the CPU port of a DSA).
I'm also not familiar with much of net/core.

If it is valid that page_pool might not have page_pool_params in a DSA
scenario, then hopefully this patch is sufficient. If it isn't valid and
something I'm doing is invoking a memory issue - then I've got my work
cut out for me :-)


Colin Foster (1):
  page_pool: fix NULL dereference crash

 net/core/page_pool.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.25.1