{"id":"CVE-2026-98798","title":"net: bcmgenet: fix NULL dereference in set_coalesce before first open","summary":"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 t…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 9f4ca05827a27ec73bf63a42732f1978b8a779af < 0d867b91598b6ed2f75998c34f4e2869631da31e","Linux >= 9f4ca05827a27ec73bf63a42732f1978b8a779af < 2294b62eaec6fd3c76a261d287f66641eeafd5f0","Linux >= 9f4ca05827a27ec73bf63a42732f1978b8a779af < d870102b5425390cab42eebbf3d19ec6a43c6734","Linux >= 9f4ca05827a27ec73bf63a42732f1978b8a779af < 19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1","Linux 4.17"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:48:43.367Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98798","references":[{"url":"https://git.kernel.org/stable/c/0d867b91598b6ed2f75998c34f4e2869631da31e"},{"url":"https://git.kernel.org/stable/c/2294b62eaec6fd3c76a261d287f66641eeafd5f0"},{"url":"https://git.kernel.org/stable/c/d870102b5425390cab42eebbf3d19ec6a43c6734"},{"url":"https://git.kernel.org/stable/c/19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.483Z","slug":"CVE-2026-98798","body":"## Overview\n\nIn 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->priv. 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.\n\n## Affected\n\n- `Linux >= 9f4ca05827a27ec73bf63a42732f1978b8a779af < 0d867b91598b6ed2f75998c34f4e2869631da31e`\n- `Linux >= 9f4ca05827a27ec73bf63a42732f1978b8a779af < 2294b62eaec6fd3c76a261d287f66641eeafd5f0`\n- `Linux >= 9f4ca05827a27ec73bf63a42732f1978b8a779af < d870102b5425390cab42eebbf3d19ec6a43c6734`\n- `Linux >= 9f4ca05827a27ec73bf63a42732f1978b8a779af < 19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1`\n- `Linux 4.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}