net: openvswitch: reject oversized nested action attrs
In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: reject oversized nested action attrs Open vSwitch stores generated flow actions as nlattrs, whose nla_len field is u16. Commit a1e64addf3ff ("net: openvswitch: remove misbehaving actions length check") allowed the total sw_flow_actions stream to grow beyond 64 KiB, which is valid, but also removed the last guard preventing a generated nested action attribute from exceeding U16_MAX. An oversized generated container can thus be closed with a truncated nla_len. A later dump or teardown then walks a structurally different stream than the one that was validated. In particular, an oversized nested CLONE/CT action may cause subsequent bytes in the generated stream to be interpreted as independent actions. Keep the larger total-action-stream behavior, but make nested action close reject generated containers that do not fit in nla_len, and return the error through all callers. For recursive SAMPLE, CLONE, DEC_TTL, and CHECK_PKT_LEN builders, trim resource-owning action-list tails in reverse construction order before discarding failed wrappers, so resources copied into the rejected tails are released before the wrappers are removed. Most failed outer wrappers are discarded by truncating actions_len after child resources have been released. CHECK_PKT_LEN also trims its parent after branch resources are gone. SET/TUNNEL close failures unwind their known tun_dst ownership directly, and SET_TO_MASKED has
CVE-2026-64531
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-64531
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "057dbc5b72e9fcac439cd561c3a539b8a0edeb92",
"lessThan": "ab855641241387db062a5e41d9ad6b8561542572",
"versionType": "git"
},
{
"status": "affected",
"version": "2532adbfe917c0e71dba2650ffc6efe396314c87",
"lessThan": "c66bd2626c2764f23764ff0f8277f44a9cfe8349",
"versionType": "git"
},
{
"status": "affected",
"version": "4b1a0ee6164c7204c68ab5a9c48c07bfe8852485",
"lessThan": "d573250d228401f707f4dbc09d11227a6215ee5f",
"versionType": "git"
},
{
"status": "affected",
"version": "e6610f9c08b4c04cf7949c10fc246c071d00e935",
"lessThan": "f1efff8858403191361a01269c6fe8dd7f55a385",
"versionType": "git"
},
{
"status": "affected",
"version": "a1e64addf3ff9257b45b78bc7d743781c3f41340",
"lessThan": "dbd14f736be02cfe73049bd801af89becd1a0749",
"versionType": "git"
},
{
"status": "affected",
"version": "a1e64addf3ff9257b45b78bc7d743781c3f41340",
"lessThan": "1b41cbe05b184f8861712f0806cc0c4f5d8c6dfe",
"versionType": "git"
},
{
"status": "affected",
"version": "a1e64addf3ff9257b45b78bc7d743781c3f41340",
"lessThan": "3f1f755366687d051174739fb99f7d560202f60b",
"versionType": "git"
},
{
"status": "affected",
"version": "6b099d285d7ed324494b6d684f377aa103856118",
"versionType": "git"
},
{
"status": "affected",
"version": "5.15.180",
"lessThan": "5.15.212",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.1.132",
"lessThan": "6.1.178",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.6.84",
"lessThan": "6.6.145",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.12.20",
"lessThan": "6.12.97",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.13.8",
"lessThan": "6.14",
"versionType": "semver"
}
],
"programFiles": [
"net/openvswitch/flow_netlink.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.14"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.14",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/openvswitch/flow_netlink.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64531
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #41067 · Revision 1
- Added to Heist Feed
- Publisher date