CVE-2026-80901

ipvs: fix the checksum validations

State: Published
Severity: Not scored
Published: Sep 4, 2026
Updated: Sep 4, 2026
Reserved: Aug 26, 2026

Description

In 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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	2a3b791e6e1169f374224d164738e9f7be703d77 to before d418d73acf8be62744dc47359dfdde8c2148845dAffected 2a3b791e6e1169f374224d164738e9f7be703d77 to before b3869d9b54e76dff64118dee4c8fd9302fcd5171Affected 2a3b791e6e1169f374224d164738e9f7be703d77 to before 9cbe2c0fdb71904ee929b1851cdc1c73341a03c0Affected 2a3b791e6e1169f374224d164738e9f7be703d77 to before 00eb23829fd08df1b5e057cb6b625996a70e7e65Affected 2a3b791e6e1169f374224d164738e9f7be703d77 to before 5558a85add073215b298f3e044ff9a6d86d714aeAffected 2a3b791e6e1169f374224d164738e9f7be703d77 to before e876b75b9020a97bbdc79721e7fc749024891c65Affected
LinuxLinux	2.6.28Affected before 2.6.28Not affected 6.1.183 through 6.1.Not affected 6.6.151 through 6.6.Not affected 6.12.103 through 6.12.Not affected 6.18.44 through 6.18.Not affected 7.1.8 through 7.1.*Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

2a3b791e6e1169f374224d164738e9f7be703d77 to before d418d73acf8be62744dc47359dfdde8c2148845dAffected
2a3b791e6e1169f374224d164738e9f7be703d77 to before b3869d9b54e76dff64118dee4c8fd9302fcd5171Affected
2a3b791e6e1169f374224d164738e9f7be703d77 to before 9cbe2c0fdb71904ee929b1851cdc1c73341a03c0Affected
2a3b791e6e1169f374224d164738e9f7be703d77 to before 00eb23829fd08df1b5e057cb6b625996a70e7e65Affected
2a3b791e6e1169f374224d164738e9f7be703d77 to before 5558a85add073215b298f3e044ff9a6d86d714aeAffected
2a3b791e6e1169f374224d164738e9f7be703d77 to before e876b75b9020a97bbdc79721e7fc749024891c65Affected

LinuxLinux

2.6.28Affected
before 2.6.28Not affected
6.1.183 through 6.1.*Not affected
6.6.151 through 6.6.*Not affected
6.12.103 through 6.12.*Not affected
6.18.44 through 6.18.*Not affected
7.1.8 through 7.1.*Not affected
7.2 and laterNot affected

References

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