Vulnerability-Lookup

GHSA-2FQ7-GW6W-F3QV

Vulnerability from github – Published: 2026-10-06 09:31 – Updated: 2026-10-06 09:31

Details

In the Linux kernel, the following vulnerability has been resolved:

net: ip_tunnel: initialize options_len before referencing options

The following command triggers a kernel panic:

ip link add d0 type dummy; ip link set d0 up ip route add 10.30.0.0/16 \ encap ip id 300 geneve_opts 4660:66:11223344 dev d0

memcpy: detected buffer overflow: 4 byte write of buffer size 0 kernel BUG at lib/string_helpers.c:1044! ... ip_tun_parse_opts.part.0.cold+0x10/0x10 ip_tun_build_state+0x116/0x2a0

On kernels built with GCC 15+ and CONFIG_FORTIFY_SOURCE, the fortified memcpy() got 0 sized destination with request of 4 bytes length:

static int ip_tun_parse_opts_geneve(...) { ... attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA]; data_len = nla_len(attr); /* == 4 */

  struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len;
  memcpy(opt->opt_data, nla_data(attr), data_len);
  /*     ^^^^^^^^^^^^^ 0 since options_len is assigned afterwards */

Fixed by initializing the counter before the options are referenced. Matching what tunnel_key_opts_set() already does.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-98240"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-06T09:18:11Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ip_tunnel: initialize `options_len` before referencing options\n\nThe following command triggers a kernel panic:\n\n  ip link add d0 type dummy; ip link set d0 up\n  ip route add 10.30.0.0/16 \\\n    encap ip id 300 geneve_opts 4660:66:11223344 dev d0\n\n  memcpy: detected buffer overflow: 4 byte write of buffer size 0\n  kernel BUG at lib/string_helpers.c:1044!\n  ...\n  ip_tun_parse_opts.part.0.cold+0x10/0x10\n  ip_tun_build_state+0x116/0x2a0\n\nOn kernels built with GCC 15+ and `CONFIG_FORTIFY_SOURCE`, the fortified\n`memcpy()` got 0 sized destination with request of 4 bytes length:\n\n  static int ip_tun_parse_opts_geneve(...)\n  {\n      ...\n      attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA];\n      data_len = nla_len(attr); /* == 4 */\n\n      struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len;\n      memcpy(opt-\u003eopt_data, nla_data(attr), data_len);\n      /*     ^^^^^^^^^^^^^ 0 since options_len is assigned afterwards */\n\nFixed by initializing the counter before the options are referenced.\nMatching what `tunnel_key_opts_set()` already does.",
  "id": "GHSA-2fq7-gw6w-f3qv",
  "modified": "2026-10-06T09:31:32Z",
  "published": "2026-10-06T09:31:32Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98240"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0f6a6beb01c068fcd5274eabf22c260039749fea"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/455ebeadf714f51e1dbbd6a022c74c9215b1cd76"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9907325257b4b382f26aafd5d9a8d47915907dd5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-98240 (GCVE-0-2026-98240)

Vulnerability from cvelistv5 – Published: 2026-10-06 08:45 – Updated: 2026-10-06 08:45

Title

net: ip_tunnel: initialize `options_len` before referencing options

Summary

In the Linux kernel, the following vulnerability has been resolved: net: ip_tunnel: initialize `options_len` before referencing options The following command triggers a kernel panic: ip link add d0 type dummy; ip link set d0 up ip route add 10.30.0.0/16 \ encap ip id 300 geneve_opts 4660:66:11223344 dev d0 memcpy: detected buffer overflow: 4 byte write of buffer size 0 kernel BUG at lib/string_helpers.c:1044! ... ip_tun_parse_opts.part.0.cold+0x10/0x10 ip_tun_build_state+0x116/0x2a0 On kernels built with GCC 15+ and `CONFIG_FORTIFY_SOURCE`, the fortified `memcpy()` got 0 sized destination with request of 4 bytes length: static int ip_tun_parse_opts_geneve(...) { ... attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA]; data_len = nla_len(attr); /* == 4 */ struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len; memcpy(opt->opt_data, nla_data(attr), data_len); /* ^^^^^^^^^^^^^ 0 since options_len is assigned afterwards */ Fixed by initializing the counter before the options are referenced. Matching what `tunnel_key_opts_set()` already does.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6664 records in the last 180 days details

References

3 references

URL	Tags
https://git.kernel.org/stable/c/9907325257b4b382f…
https://git.kernel.org/stable/c/0f6a6beb01c068fcd…
https://git.kernel.org/stable/c/455ebeadf714f51e1…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: bb5e62f2d547c4de6d1b144cbce2373a76c33f18 , < 9907325257b4b382f26aafd5d9a8d47915907dd5 (git) Affected: bb5e62f2d547c4de6d1b144cbce2373a76c33f18 , < 0f6a6beb01c068fcd5274eabf22c260039749fea (git) Affected: bb5e62f2d547c4de6d1b144cbce2373a76c33f18 , < 455ebeadf714f51e1dbbd6a022c74c9215b1cd76 (git)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.18.54 , ≤ 6.18.* (semver) Unaffected: 7.2.8 , ≤ 7.2.* (semver) Unaffected: 7.3-rc4 , ≤ * (original_commit_for_fix)

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{
  "containers": {
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          "programFiles": [
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              "status": "affected",
              "version": "bb5e62f2d547c4de6d1b144cbce2373a76c33f18",
              "versionType": "git"
            },
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          "versions": [
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              "status": "unaffected",
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              "status": "unaffected",
              "version": "7.2.8",
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              "status": "unaffected",
              "version": "7.3-rc4",
              "versionType": "original_commit_for_fix"
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
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Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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