GHSA-MP45-VJM2-GVHG
Vulnerability from github – Published: 2026-09-04 18:31 – Updated: 2026-09-04 18:31In the Linux kernel, the following vulnerability has been resolved:
ipvs: fix the checksum validations
ip_vs_in_icmp_v6() is missing checksum validation for ICMPv6 packets from clients. In fact, as for TCP/UDP we should validate the checksum for ICMP packets only when we mangle the packets on MASQ or on reply for tunnel.
Also, Sashiko points out that handle_response_icmp() being common for IPv4 and IPv6 is missing the pseudo-header calculation while validating ICMPv6 messages from real servers which is a problem if checksum is not validated by the hardware.
Fix the problems by creating ip_vs_checksum_common_check() helper and use it for TCP/UDP/ICMP both for IPv4 and IPv6. Rely on the nf_checksum() for validating the ICMP messages but use it also for TCP and UDP.
Use correct IP offset for IP_VS_DBG_RL_PKT for TCP/UDP/SCTP.
IPVS packets (TCP/UDP/SCTP/ICMP) do not need checksum validation on LOCAL_OUT (local clients or local real servers) and on FORWARD (traffic from servers on LAN). Do it only on LOCAL_IN, in case nf_checksum() is not called on PRE_ROUTING.
Also, ip_vs_checksum_complete() can be marked static.
{
"affected": [],
"aliases": [
"CVE-2026-80901"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-04T18:17:58Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: fix the checksum validations\n\nip_vs_in_icmp_v6() is missing checksum validation for ICMPv6\npackets from clients. In fact, as for TCP/UDP we should\nvalidate the checksum for ICMP packets only when we\nmangle the packets on MASQ or on reply for tunnel.\n\nAlso, Sashiko points out that handle_response_icmp() being\ncommon for IPv4 and IPv6 is missing the pseudo-header\ncalculation while validating ICMPv6 messages from real\nservers which is a problem if checksum is not validated\nby the hardware.\n\nFix the problems by creating ip_vs_checksum_common_check()\nhelper and use it for TCP/UDP/ICMP both for IPv4 and IPv6.\nRely on the nf_checksum() for validating the ICMP messages\nbut use it also for TCP and UDP.\n\nUse correct IP offset for IP_VS_DBG_RL_PKT for TCP/UDP/SCTP.\n\nIPVS packets (TCP/UDP/SCTP/ICMP) do not need checksum\nvalidation on LOCAL_OUT (local clients or local real\nservers) and on FORWARD (traffic from servers on LAN).\nDo it only on LOCAL_IN, in case nf_checksum() is not\ncalled on PRE_ROUTING.\n\nAlso, ip_vs_checksum_complete() can be marked static.",
"id": "GHSA-mp45-vjm2-gvhg",
"modified": "2026-09-04T18:31:34Z",
"published": "2026-09-04T18:31:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80901"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/00eb23829fd08df1b5e057cb6b625996a70e7e65"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5558a85add073215b298f3e044ff9a6d86d714ae"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9cbe2c0fdb71904ee929b1851cdc1c73341a03c0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b3869d9b54e76dff64118dee4c8fd9302fcd5171"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d418d73acf8be62744dc47359dfdde8c2148845d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e876b75b9020a97bbdc79721e7fc749024891c65"
}
],
"schema_version": "1.4.0",
"severity": []
}
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