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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?a4Nx5HMFga12o0R8bDAyeJjRQ1j2S7yp0P9WEz9g2bVLZBo+o9ciBNl4ZUOi?= =?us-ascii?Q?IOjP+4tyabnQiaeSo57lIQrDA68LRVWUW5Ok3hS2+/XWkXVdofYlrDm8ynKZ?= =?us-ascii?Q?gfh12xzzjeEeioPS+lkM3L/P/qMDJtBCNHKxifRZXxw6HDRLUKsORxfETNrI?= =?us-ascii?Q?NRfIwAmQionrvDDjBKkFFD1uEOT25iY1X2oDwVgbXVv15XaOTQOqAXHzyznQ?= =?us-ascii?Q?RnTliS1RTvmmPLYXHLHVf1+Teb3taivvORX8OT59YdmYkD9qDxFAm+LY6y22?= =?us-ascii?Q?SUjb5qaSZ2WEhjIt3M1lnz5XHLXdW0YbBX+hj08fhoSxoXDUI9nGtMLT8bXt?= =?us-ascii?Q?+qZ3PdsOW16OeQ1WjzC+D65gNSB70fi5oLrSkDK1+0V0ay46Bm+08WC+bn2g?= =?us-ascii?Q?tIy1I1PvEMIGhI2DG0IYMotzhVNxMJ1KTK9IqBsmmzMbwWrO58sOi51QNfDt?= =?us-ascii?Q?xdtvRTA0PYW2b/k9ITY+B7EDErr1ibUcybpygQJfMUijiMA1/QI68lZKoQNb?= =?us-ascii?Q?5B+5I7kXqU84UlFriQb6bcl0jJdyfrSc4Ix1JqRo1ioiiX+S3PPLPMHgesGX?= =?us-ascii?Q?XxZgOqzs6cg2PTwm9UAc5cQdDCU8e7UzwOrdUIPtiLxzxgCwvmnWWWE7A23h?= =?us-ascii?Q?/lGvJ6PMSTMF6Ah3EE7vydmVW7V07jnSR3Agt63r3tvXE5I/0pDn2e/2pe5C?= =?us-ascii?Q?8ZG+Vx1a7PIOmQu9Ze+dp6Pn3Y0bi03c6uHGF3cMZUYuXWug3DdYaI1jjlRq?= =?us-ascii?Q?dtxjDysb+fbJrdETSvXdHRHZiezY50tZdKdcUcF901d4ssAe7cldfU89XXHu?= =?us-ascii?Q?QZNmjs5lyraXuLswa3nxoWWrmd7Q7BCA2Da6wvZn82Ugp0y3B3o+KEZ1XUjY?= =?us-ascii?Q?27yTzhCwHs3wovbVVj4IDoteu/3zficXko9ExYg1ZKdTXXU8IsiyUyGwnVlR?= =?us-ascii?Q?mzKNqNc6fIJMtnhfWdIQVGu2FHp86vAhabrr/aoDOoDTBCbYW7VF5cEXb0cL?= =?us-ascii?Q?wUV5MnMvGR3pPgBa0ldEXlXsatDMpAQf2MWxWLChrjA4YXjyh28A1a7cuqCF?= =?us-ascii?Q?FNzUJCwVcG6vKu5T2bwHIrFOrS4Eo0vKLzZOQb98SgLm5bOpBOWkSUwu6OjF?= =?us-ascii?Q?+ZDfStpuoX8KY5PXqFrxRyUhTuvIi5NwIXr9glDLeyw54xx3iwqRvoWQ/Xrs?= =?us-ascii?Q?8EWIDFEP17HnhSG690vXFPlhSOD4m/+EXfIh3XxpfxY3MsIiVvZyDmaOa6AC?= =?us-ascii?Q?d5OcykNodC9ih2WRcj03Mi/ZX3cijifxDNo7RDckg1Ek1A1NVUQv2SqX7b72?= =?us-ascii?Q?/0vKtCaBWBdN4WXIs3ipATcofau0zTa4K9qC34QZUOACaVCLVFPz/wIUWD0X?= =?us-ascii?Q?RDgqLBWujIFMhjgRHMpG/kys0ZgeuLYFkfBNRSeqI2SHpSt3AznmiyioTrmj?= =?us-ascii?Q?vmULm0DvRD/+HAkuq9v//liKVDvSJAU09nUFgnfTKFR3aSg5nL8LeTU1qHP5?= =?us-ascii?Q?bdydA7elOr94Bmou4MdoHbQa00QTa2Gu1BeC1N4oBkzuW1aYgY7iIhhHyeaB?= =?us-ascii?Q?9UItodMOyMar1fcxxIe+5QhNQsenoebDXFq0C3hROxZdmP6tL9LFsbklT4vz?= =?us-ascii?Q?RS+pg68rt8Lhrz7yY1l1zWu8KyvtPmf/LDB0f2LeM8YiFv609pZBMI2/y8+u?= =?us-ascii?Q?HKY4srWisXxh/lv7KtdzdSYIfQwDpbiS3TcaTu9hHwIjJPVGJ4xwr1oMOPI4?= =?us-ascii?Q?Z7fj2yS9BQ=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 76f39120-d051-4b5f-a3a7-08deee4200fd X-MS-Exchange-CrossTenant-AuthSource: SA3PR12MB7901.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jul 2026 13:53:58.6493 (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: +lM10US21bOCYG8CUldLxR8tT3gTRsZuJ62JAtvOs+PojGSu2OZiho/COwDbtAWPTBgby4SH+eIdBl4HhBmmVA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH8PR12MB9790 On Thu, Jul 30, 2026 at 12:59:26PM +0000, Zihan Xi wrote: > fib_nlmsg_size() still estimates nexthop space as if every gateway is > encoded as an IPv4 RTA_GATEWAY attribute. IPv4 routes can also carry an > IPv6 gateway, which fib_nexthop_info() dumps as RTA_VIA. > > As a result, route notifications can allocate an skb that is too small. > fib_dump_info() then fails with -EMSGSIZE and rtmsg_fib() hits the > WARN_ON() that marks such failures as a fib_nlmsg_size() bug. With > panic_on_warn set, this becomes a kernel panic. > > Mirror the actual nexthop dump layout in fib_nlmsg_size(): account for > IPv6 nexthop gateways dumped as RTA_VIA, for the no-header rtnexthop > layout used inside RTA_MULTIPATH, and for RTA_FLOW only when it is > actually present. > > Fixes: d15662682db2 ("ipv4: Allow ipv6 gateway with ipv4 routes") > Cc: stable@vger.kernel.org > Reported-by: Vega > Assisted-by: Codex:gpt-5.4 > Signed-off-by: Zihan Xi Reviewed-by: Ido Schimmel