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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?ixVYq77dEEvKxMTdKCqDftH2gY2KY5jz/6SZ4ng65t/hWI+jEtSloD+qx2m5?= =?us-ascii?Q?GsBBPRSZvj5wCfGeYeg66LB3nnQTe1qQkr0raQdJMzVZiNJdh4E4pYfRXI//?= =?us-ascii?Q?vpE0GbU7FiDZAkZwWb9Q6018OtaCyiDj4do5GGdfpbvOd8S05vY+H1cXCUhs?= =?us-ascii?Q?p02CwoW2aBRM2yCN/hSBKG7/rNbx3pTuuXnuPcmc9OMHKrCHySfBjqwPctci?= =?us-ascii?Q?UbtRs/0BwhPJDWfBZEZu2P/gp8GMXYn9V2ld5irNOVjNwS3NQAdyAEbD7HYD?= =?us-ascii?Q?zAPyUlWI1A+6hGpqjN6XgaN5Wp5j5GYB9PetFFTGzfSBovengyb7lREiWlgl?= =?us-ascii?Q?AlXiGVpu6hO+Q1Pv3/6nRBTtdxoTvPilmB03zenPKevyuf1z25sFsoH6F8Rv?= =?us-ascii?Q?hixtLEWXjiD5U5mO4NVrEqY37vofaelpMbL1CnvA0B65dydb5W58BORqRB/z?= =?us-ascii?Q?7WPR5KagaaGXTdQkrxnlNJnMKROSj4jpC1PBK0EgyecqI4XKWHCMOdvCy50W?= =?us-ascii?Q?BeAMbUBWQ6VGsRIFZ3WpHyyViSiPvoXWeriSILDj7OB5AVFk77Vz/WOmarvI?= =?us-ascii?Q?eN9cX8AHafkOc3S4hga3dCCRQpU2KBH9gRgkbhWpVgd4xOJfr/anJ7PFv1qe?= =?us-ascii?Q?hJYk5ha+DXKZ2KZNtUJEHn/E006xQqDMKF5BDVAinVm/4PFUyS0CI51rBlQB?= =?us-ascii?Q?Him4FJmTy+1IQ9NLIeB10ermLL4lkMfS+MSDklmIM4Y6rxN2oqi8z/QBxPtt?= =?us-ascii?Q?eXSaiLUSubrjV3UKdQEF8dkEO8RRtB+GNea96wDzt6NipcHKYBeNcIw1mJtx?= =?us-ascii?Q?iVC6oS+j0WX+5nuiK7RhAk6ZCMPfpnF0JTJPrU4qCTn9pk0vfHYuj27aWJGv?= =?us-ascii?Q?KrlHLW8/la+1Lb1XBSxGiE1d7p88nhLQfIRaIn2UWPYuTgAttSdotflszarp?= =?us-ascii?Q?rqqA0kauLzdY1X8K6TxbLwFEJAfFFaleyfRXjefkO12EA78zbSl6+UsvvDSo?= =?us-ascii?Q?w3VjnuTsGXYRV46dMEO+QgGFBn5rKmlD0Hk2PGD+NgVPPtn++4sEoovsHchv?= =?us-ascii?Q?O3tYherRAGkofD6OU5z7wHV1A6usOC74+Qwn6lL8RHxyCV5LKTzN4FI5XASl?= =?us-ascii?Q?Wd2xBJARKv3hXrMT4Ffh5XWtuGiYVzEnlg23oqnsNwDb+84jQ6tNa4ZqrSa2?= =?us-ascii?Q?5/E6uOawmC3Da6JbNUgJr2EUT3YQ3X+EPMGgdVrtyG6oMrzH+VATMoB6L6br?= =?us-ascii?Q?Fl4YH14PfRgad15VgladjcP/VTqtQZicN7PVKrEvLbB5ljdiQVe4y7H5y1AZ?= =?us-ascii?Q?l1YBTweq2nwb9VJ2YtPgyRR1ne4Q5zvdCO5vADVY36Yk031cq8u7gZMW9kXf?= =?us-ascii?Q?A8bmZ4/D9MUhK5/+MngOFVVMn2tyrUGjd4rpQECjArOtslOfrGKrk6fDoKib?= =?us-ascii?Q?+9AD6K0El8g4yNQw6YtZ0HCAslfxeVTYX7OZUkMDvydREvsAvtGKOw0kvZxw?= =?us-ascii?Q?XQIic/UgfCkw1fKVzbfmUQ2/ELiFzo4raRxhUUBOzt/4mnzF1xU4pcn8MxiO?= =?us-ascii?Q?NDK8kgWhvE8vs5XytPJKQ78uE40pbB6CgZviXaedUpK4MPd/d45M2gtLWfJu?= =?us-ascii?Q?mQcA0wFRnt7jDkKcH57q+nw6AQoZmB786JpVS2pgESjTb29doMoIeIMHlg84?= =?us-ascii?Q?O5Qwo2soVYl0sjN3emGpcjJZodohhIES+hqBmvu7SnpRP+AudkDMOhaTCEEP?= =?us-ascii?Q?Tt2d0jNGwA=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 8db8aee0-a45c-4e74-7379-08de91653096 X-MS-Exchange-CrossTenant-AuthSource: SA3PR12MB7901.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Apr 2026 09:41:32.9357 (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: 9O9Wyz7xweFY6IPrqSgzXmw+im+VyiC7gvxrWxFBTcnlcKIhJowoiFvTN80nHr2Q5Soa0NAYsMN0rf4XmGESbg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR12MB7177 On Thu, Apr 02, 2026 at 09:26:13AM +0200, Fernando Fernandez Mancera wrote: > When querying a nexthop object via RTM_GETNEXTHOP, the kernel currently > allocates a fixed-size skb using NLMSG_GOODSIZE. While sufficient for > single nexthops and small Equal-Cost Multi-Path groups, this fixed > allocation fails for large nexthop groups like 512 nexthops. > > This results in the following warning splat: > > WARNING: net/ipv4/nexthop.c:3395 at rtm_get_nexthop+0x176/0x1c0, CPU#20: rep/4608 > [...] > RIP: 0010:rtm_get_nexthop (net/ipv4/nexthop.c:3395) > [...] > Call Trace: > > rtnetlink_rcv_msg (net/core/rtnetlink.c:6989) > netlink_rcv_skb (net/netlink/af_netlink.c:2550) > netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344) > netlink_sendmsg (net/netlink/af_netlink.c:1894) > ____sys_sendmsg (net/socket.c:721 net/socket.c:736 net/socket.c:2585) > ___sys_sendmsg (net/socket.c:2641) > __sys_sendmsg (net/socket.c:2671) > do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) > entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) > > > Fix this by allocating the size dynamically using nh_nlmsg_size() and > using nlmsg_new(), this is consistent with nexthop_notify() behavior. In > addition, adjust nh_nlmsg_size_grp() so it calculates the size needed > based on flags passed. While at it, also add the size of NHA_FDB for > nexthop group size calculation as it was missing too. > > This cannot be reproduced via iproute2 as the group size is currently > limited and the command fails as follows: > > addattr_l ERROR: message exceeded bound of 1048 > > Fixes: 430a049190de ("nexthop: Add support for nexthop groups") > Reported-by: Yiming Qian > Closes: https://lore.kernel.org/netdev/CAL_bE8Li2h4KO+AQFXW4S6Yb_u5X4oSKnkywW+LPFjuErhqELA@mail.gmail.com/ > Signed-off-by: Fernando Fernandez Mancera > Reviewed-by: Eric Dumazet Reviewed-by: Ido Schimmel