CVE-2026-98798 (GCVE-0-2026-98798)
Vulnerability from cvelistv5
Published
2026-10-18 15:48
Modified
2026-10-21 12:57
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: net: bcmgenet: fix NULL dereference in set_coalesce before first open The Rx ring priv and index are only set in bcmgenet_init_rx_ring(), which runs at open. Setting the Rx coalescing parameters on an interface that was never opened, e.g. "ethtool -C eth0 rx-usecs 50", dereferences a NULL ring->priv. The oops happens with RTNL held, so networking stays stuck until a reboot: Unable to handle kernel paging request at virtual address 0000000000002788 pc : bcmgenet_set_rx_coalesce.isra.0+0x10/0x88 lr : bcmgenet_set_coalesce+0xe8/0x180 Call trace: bcmgenet_set_rx_coalesce.isra.0+0x10/0x88 (P) __ethnl_set_coalesce.isra.0+0x490/0x570 ethnl_set_coalesce+0x48/0xc0 ethnl_default_set_doit+0xf4/0x230 genl_family_rcv_msg_doit+0xe8/0x160 genl_rcv_msg+0x220/0x2a0 netlink_rcv_skb+0x68/0x140 genl_rcv+0x40/0x60 netlink_unicast+0x338/0x3c0 netlink_sendmsg+0x19c/0x3f8 __sock_sendmsg+0x64/0xc0 __sys_sendto+0x124/0x198 __arm64_sys_sendto+0x30/0x48 Set priv and index at probe. Writing the registers while the interface is down is harmless because open resets the MAC and bcmgenet_init_rx_coalesce() reapplies the stored values. It was observed on a Raspberry Pi CM4, but should apply to all other genet devices.
References
Impacted products
Vendor Product Version
Linux Linux Version: 9f4ca05827a27ec73bf63a42732f1978b8a779af
Version: 9f4ca05827a27ec73bf63a42732f1978b8a779af
Version: 9f4ca05827a27ec73bf63a42732f1978b8a779af
Version: 9f4ca05827a27ec73bf63a42732f1978b8a779af
Version: 9f4ca05827a27ec73bf63a42732f1978b8a779af
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/broadcom/genet/bcmgenet.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "versionType": "git"
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            {
              "lessThan": "0d867b91598b6ed2f75998c34f4e2869631da31e",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "2294b62eaec6fd3c76a261d287f66641eeafd5f0",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "d870102b5425390cab42eebbf3d19ec6a43c6734",
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              "versionType": "git"
            },
            {
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              "version": "9f4ca05827a27ec73bf63a42732f1978b8a779af",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/broadcom/genet/bcmgenet.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.17"
            },
            {
              "lessThan": "4.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.160",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.113",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.56",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.10",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T12:57:06.002Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/213ff02ab26a4543ef02b4db393bbdd5fa5679a7"
        },
        {
          "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"
        }
      ],
      "title": "net: bcmgenet: fix NULL dereference in set_coalesce before first open",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98798",
    "datePublished": "2026-10-18T15:48:43.367Z",
    "dateReserved": "2026-09-25T10:25:14.370Z",
    "dateUpdated": "2026-10-21T12:57:06.002Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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