{"id":"CVE-2026-98798","summary":"net: bcmgenet: fix NULL dereference in set_coalesce before first open","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bcmgenet: fix NULL dereference in set_coalesce before first open\n\nThe Rx ring priv and index are only set in bcmgenet_init_rx_ring(),\nwhich runs at open. Setting the Rx coalescing parameters on an interface\nthat was never opened, e.g. \"ethtool -C eth0 rx-usecs 50\", dereferences\na NULL ring-\u003epriv. The oops happens with RTNL held, so networking\nstays stuck until a reboot:\n\n  Unable to handle kernel paging request at virtual address 0000000000002788\n  pc : bcmgenet_set_rx_coalesce.isra.0+0x10/0x88\n  lr : bcmgenet_set_coalesce+0xe8/0x180\n  Call trace:\n   bcmgenet_set_rx_coalesce.isra.0+0x10/0x88 (P)\n   __ethnl_set_coalesce.isra.0+0x490/0x570\n   ethnl_set_coalesce+0x48/0xc0\n   ethnl_default_set_doit+0xf4/0x230\n   genl_family_rcv_msg_doit+0xe8/0x160\n   genl_rcv_msg+0x220/0x2a0\n   netlink_rcv_skb+0x68/0x140\n   genl_rcv+0x40/0x60\n   netlink_unicast+0x338/0x3c0\n   netlink_sendmsg+0x19c/0x3f8\n   __sock_sendmsg+0x64/0xc0\n   __sys_sendto+0x124/0x198\n   __arm64_sys_sendto+0x30/0x48\n\nSet priv and index at probe. Writing the registers while the interface\nis down is harmless because open resets the MAC and\nbcmgenet_init_rx_coalesce() reapplies the stored values.\n\nIt was observed on a Raspberry Pi CM4, but should apply to all other\ngenet devices.","modified":"2026-10-19T02:47:23.741261513Z","published":"2026-10-18T15:48:43.367Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98798.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/0d867b91598b6ed2f75998c34f4e2869631da31e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2294b62eaec6fd3c76a261d287f66641eeafd5f0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d870102b5425390cab42eebbf3d19ec6a43c6734"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98798.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98798"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9f4ca05827a27ec73bf63a42732f1978b8a779af"},{"fixed":"0d867b91598b6ed2f75998c34f4e2869631da31e"},{"fixed":"2294b62eaec6fd3c76a261d287f66641eeafd5f0"},{"fixed":"d870102b5425390cab42eebbf3d19ec6a43c6734"},{"fixed":"19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98798.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.17.0"},{"fixed":"6.12.113"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.56"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98798.json"}}],"schema_version":"1.9.0"}