{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-98030",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-98030"
  ],
  "published": "2026-09-25T10:24:31Z",
  "summary": "net: dsa: bcm_sf2: bound the CFP rule dump by the caller's buffer size",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: bcm_sf2: bound the CFP rule dump by the caller's buffer size\n\nbcm_sf2_cfp_rule_get_all() walks the whole cfp.unique bitmap into\nrule_locs[] without consulting nfc->rule_cnt, which is how many entries\nthe caller had room for.  ETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN\nand the ioctl sizes the buffer from the rule_cnt userspace passes in, so\nonce an admin has installed CFP rules any user can ask for fewer slots\nthan there are rules and run off the end of the allocation.  A rule_cnt\nof 0 leaves the buffer pointer NULL and the walk dereferences it.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.189",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-98030"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ca49c526291d7cd3a5cb49b0edd7f50a5ae7176e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8e41ce02589c92356bfd8ef62f6ceff840546e1a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f2cf4ef2d94fc15fd2e21c131fc1ab3f76125bf4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f5e93162b3dd195bfda815e8f7a39aaf1d45437b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f1a2869b3629c0e8394b77b38cb9f19a018c653c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/fd1a78c16b1f6978c09cf048e15f349732e4c707"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b231b6d8516d3fe0d4bba549908e08d26a4531a5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/cdb719f4b8596d9ccee2d56d204c2c4dce982f46"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-10-03T11:04:09Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.0,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The trigger is the local SIOCETHTOOL ioctl with ETHTOOL_GRXCLSRLALL on a bcm_sf2 DSA user port. The path is ethtool_get_rxnfc() -> dsa_user_get_rxnfc() -> bcm_sf2_get_rxnfc() -> bcm_sf2_cfp_rule_get_all(). The bad rule_cnt comes from userspace, and no packet from a remote peer is involved.\nAC:H - The overflow needs CFP rules installed beyond the default at bit 0 of cfp.unique, since the walk starts at index 1. Installing them via ETHTOOL_SRXCLSRLINS needs CAP_NET_ADMIN over the switch's netns, so the unprivileged attacker cannot create the rule state. Once rules exist, the bug fires every time.\nPR:L - ETHTOOL_GRXCLSRLALL is on ethtool's no-capability list in net/ethtool/ioctl.c, so any unprivileged local user who can open a socket in the netns holding the DSA port can send the dump request.\nUI:N - The attacker issues the ioctl themselves and picks rule_cnt. No other user has to act.\nS:U - Both the memory corruption and the leak stay inside the kernel's own security authority, with no VM or IOMMU boundary crossed.\nC:H - After the walk, nfc->rule_cnt holds the real rule count, which can be larger than the buffer. ethtool_rxnfc_copy_to_user() then copies rule_cnt*4 bytes from the undersized kcalloc buffer to userspace. That leaks up to about 1 KB of adjacent heap from a slab cache the attacker chooses.\nI:H - bcm_sf2_cfp_rule_get_all() writes u32 rule indices past a kcalloc(rule_cnt) buffer sized by the user. This is a heap out-of-bounds write into neighbouring objects in a slab cache the attacker picks, and it can corrupt kernel data structures.\nA:H - With rule_cnt=0 the rule_locs buffer stays NULL, so the walk writes through a NULL pointer and the kernel oopses. Any user can repeat this at will once rules are installed. Heap corruption from the out-of-bounds write can also crash the system."
    }
  }
}