CVE-2026-74657
ipv4: Fix fib_nlmsg_size() for RTA_VIA nexthops
At a glance
- Source
- NVD
- EPSS
- EPSS 0.18 % · percentile 7 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Received
Description
In the Linux kernel, the following vulnerability has been resolved: ipv4: Fix fib_nlmsg_size() for RTA_VIA nexthops fib_nlmsg_size() still estimates nexthop space as if every gateway is encoded as an IPv4 RTA_GATEWAY attribute. IPv4 routes can also carry an IPv6 gateway, which fib_nexthop_info() dumps as RTA_VIA. As a result, route notifications can allocate an skb that is too small. fib_dump_info() then fails with -EMSGSIZE and rtmsg_fib() hits the WARN_ON() that marks such failures as a fib_nlmsg_size() bug. With panic_on_warn set, this becomes a kernel panic. Mirror the actual nexthop dump layout in fib_nlmsg_size(): account for IPv6 nexthop gateways dumped as RTA_VIA, for the no-header rtnexthop layout used inside RTA_MULTIPATH, and for RTA_FLOW only when it is actually present.
References
- https://git.kernel.org/stable/c/57195f0ab5cfbb5ee0864e5aff15ceb48f5a5e28
- https://git.kernel.org/stable/c/0f0ca602941d0a81ae9514943ca06c55159c6385
- https://git.kernel.org/stable/c/5307a53599fa762c06e475ee4a375252074fd324
- https://git.kernel.org/stable/c/7f80ad373ce4a7af5367ff273cea0f16e91387f3
- https://git.kernel.org/stable/c/4a5dfbae5179f6574695012a980476254df2d295
- https://git.kernel.org/stable/c/a59edda6eda1252340354322d8ab318b2e9052fb
- https://git.kernel.org/stable/c/9b22f13524fa0de0d963bbd3002df6c28bae3395
- https://git.kernel.org/stable/c/4ff9548d84945d2cbf9e4c207288063a200ea397
European references
- ENISA EUVD · EUVD-2026-64594
- GCVE · GCVE-0-2026-74657
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1333 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1286 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1232 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1163 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1090 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected d15662682db232da77136cd348f4c9df312ca6f9 < 57195f0ab5cfbb5ee0864e5aff15ceb48f5a5e28 ; affected d15662682db232da77136cd348f4c9df312ca6f9 < 0f0ca602941d0a81ae9514943ca06c55159c6385 ; affected d15662682db232da77136cd348f4c9df312ca6f9 < 5307a53599fa762c06e475ee4a375252074fd324 ; affected d15662682db232da77136cd348f4c9df312ca6f9 < 7f80ad373ce4a7af5367ff273cea0f16e91387f3 ; affected d15662682db232da77136cd348f4c9df312ca6f9 < 4a5dfbae5179f6574695012a980476254df2d295 ; affected d15662682db232da77136cd348f4c9df312ca6f9 < a59edda6eda1252340354322d8ab318b2e9052fb |
| Linux · Linux | affected 5.2 ; unaffected 0 < 5.2 ; unaffected 5.10.267 ≤ 5.10.* ; unaffected 5.15.216 ≤ 5.15.* ; unaffected 6.1.183 ≤ 6.1.* ; unaffected 6.6.152 ≤ 6.6.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |