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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , horms@kernel.org, kuniyu@google.com Subject: Re: [PATCH net] neigh: let neigh_xmit take skb ownership Message-ID: <20260426101225.GA151178@shredder> References: <20260424145843.74055-1-fw@strlen.de> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260424145843.74055-1-fw@strlen.de> X-ClientProxiedBy: TL2P290CA0029.ISRP290.PROD.OUTLOOK.COM (2603:1096:950:3::19) To SA3PR12MB7901.namprd12.prod.outlook.com (2603:10b6:806:306::12) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SA3PR12MB7901:EE_|CH3PR12MB8354:EE_ X-MS-Office365-Filtering-Correlation-Id: 1f5e26ce-f31a-4948-71a3-08dea37c562d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|366016|56012099003|22082099003|18002099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SA3PR12MB7901.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(366016)(56012099003)(22082099003)(18002099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?AAsKH3O/dPcqw/iGL+SoUJwauMSTmZ7Yj3vz2eCzYdA9EQnf70O4y5jVtxr3?= =?us-ascii?Q?WCsroKyPZu1J8fZ/ONyKf6yZgDTFLcpeoZQT4NntVsRsOZiObsvb+XsCI76g?= =?us-ascii?Q?XjNntYs3polZF2RgNzxue8C7Yy3FdIwdF8ddHfNePJ5Op3YDjjXtfJ3ymTBZ?= =?us-ascii?Q?6rXAeTWTBfeZyb3BkQi14e3banLupfmwGHCbfIQw+ZUX/pmhB/Qlv9Wlmqp4?= =?us-ascii?Q?0ShTyxXv2JQ1xUxpwTKXdoAiV50Ej0wJFr5x3le4PPYNZqP8cEMCQFenj8b4?= =?us-ascii?Q?K6p4AdWVoJ1WSgV8dgTvCH6M6pV1n8CBCO1Kiuj0tzpCZD5XiTmGMKO1WmFV?= =?us-ascii?Q?Ru43muws+qBoCLaNhIz6Q2IsXsYuVMmV/+wrTnzPaYro3jyHLn2HrdWTapKJ?= =?us-ascii?Q?N7M1gzDVmGH+VikooEEtthlQmgsKVqaK/DF1uD1d9wNu8v78Erb++nBU58rt?= =?us-ascii?Q?giZXUAPgPocaOxDz61Xy2EEyrb3EWIC8BhfYwsVaIzcsRtYTGwRy660C3dru?= =?us-ascii?Q?FYytTP35YkxC5Odr5R1xB76GW2C0JRgKd5w2Ohd4kmmgmfzhngKr9qO0uvvq?= =?us-ascii?Q?XmdFvXbIDnpLYYc4F3sWZBfMA3XRzCGcBVh9atuDXHQRTbXvqEYduWmB4euF?= =?us-ascii?Q?fAH8hGNr0i/WQ95/2lN5PWxpaifSKVbqEwaMCu4KffP9tjkV8raun2C5nBVu?= =?us-ascii?Q?/6jpOTU4n1jFsUj12x+NIC8+ybEi7TWsROk/PfJ2RJI/m9O9dsSQjtms0Lag?= =?us-ascii?Q?SPp9fVoP6RLBzqpiBBz7PamAgpC3YSw/ff9YDVsLS6k01VbJMDRywYcwkyZh?= =?us-ascii?Q?koi30/6XTtwyTIvIAQfhc+Rqcqh5TrfX1+VTZerw1h8xF6JaS/IKVueTs8Eh?= =?us-ascii?Q?PkH/SeaI5cXTZIbBXCHDb1rxP8O/Dq6UHovQYPntRX1Lxqi/RbDqQqi5qkRG?= =?us-ascii?Q?ZHwIDHWQr77ZH+GResODyk5mMEboeYepLP5vkHIPsG0+yRXyl6f0qD8iSvZ2?= =?us-ascii?Q?o73bwzS69GBYjOgD218ZZJwVo5KJPM7aORBw6vx3CIp0js9fuyqigk7GaXeq?= =?us-ascii?Q?bn3vYCCk0kScrzVoJ4brRmsEip3F3cs6S6mzWeVW6tMYHjnb8jsuq9YimjJS?= =?us-ascii?Q?PAfwCCLKEFykMWsu+JCsu5CiL2zCsm7l9jAuLqK4yPgKTEluo8TOC0MZzZS/?= =?us-ascii?Q?MUL6Ti2la/LxctIKILpDuVA6Mv6YIY3ULMB7F9PTOGkYpy5en7wUTAMxlMME?= =?us-ascii?Q?g8oAxT4Vsh/VslyZrfzA50gBuKOOJ0n+9xM4m5cCsSEfuqAOjKzzppMeKazf?= =?us-ascii?Q?WWOOlHeEokX8v62h9waCQ4/LV3nGLb0fqTdvfbjzkBjJCduVjBzTascalXFI?= =?us-ascii?Q?mZicZwVzBPx6QXYiZG6B0SKQtIYzjIGYdRoCkE/wqZWSbRsbHG85UHRX9R/K?= =?us-ascii?Q?xVTCAyYyzfbsy846AWm+DAHsJnwe9XpxLyaZx/+UraQwrtuVUHoQfX/sY5ui?= =?us-ascii?Q?3jEUvl0WgF/Se68FU6nTw9+jHm09Ip7Mdo29dsh+c9+N6J5NHWZb50P+VleC?= =?us-ascii?Q?s9/LSLqXsV3qXGXT9lGstkjhRbjKjXdMKEpsx2EwtrXvGU5m5ZcZMMosGmWF?= =?us-ascii?Q?IFyqd41cimJelSmn7o2NHCfDkzgMZHjjXMWGPxUsCfbPcn3s7waDm5/dIy8N?= =?us-ascii?Q?CdnQ/NoZXdPO8lkXWNcDWxD1vw5Im7M3cYKTt+q0A6mA2JIV?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1f5e26ce-f31a-4948-71a3-08dea37c562d X-MS-Exchange-CrossTenant-AuthSource: SA3PR12MB7901.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Apr 2026 10:12:35.1868 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: MnpQfmLg9yB3CQ0xjb1AJPMiK+01NvTjF+d8eKw8CGoKoUPIXwwHFOGMkpwz23nFV0BxmK982Vw1IEISVDNbfA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR12MB8354 On Fri, Apr 24, 2026 at 04:58:38PM +0200, Florian Westphal wrote: > neigh_xmit always releases the skb, except when no neighbour table is > found. But even the first added user of neigh_xmit (mpls) relied on > neigh_xmit to release the skb (or queue it for tx). > > sashiko reported: > If neigh_xmit() is called with an uninitialized neighbor table (for > example, NEIGH_ND_TABLE when IPv6 is disabled), it returns -EAFNOSUPPORT > and bypasses its internal out_kfree_skb error path. Because the return > value of neigh_xmit() is ignored here, does this leak the SKB? > > Assume full ownership and remove the last code path that doesn't > xmit or free skb. > > Fixes: 4fd3d7d9e868 ("neigh: Add helper function neigh_xmit") > Signed-off-by: Florian Westphal Reviewed-by: Ido Schimmel