netfilter: nf_conncount: fix zone comparison in tuple dedup
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conncount: fix zone comparison in tuple dedup The "already exists" dedup logic in __nf_conncount_add() decides whether a connection has already been counted and can be skipped instead of incrementing the connlimit count. It compares the conntrack zone of a list entry with the zone of the connection being added using nf_ct_zone_id() and nf_ct_zone_equal(), passing conn->zone.dir or zone->dir as the direction argument. Those helpers take enum ip_conntrack_dir values: IP_CT_DIR_ORIGINAL is 0 and IP_CT_DIR_REPLY is 1. However, zone->dir is a u8 bitmask: NF_CT_ZONE_DIR_ORIG is 1, NF_CT_ZONE_DIR_REPL is 2 and NF_CT_DEFAULT_ZONE_DIR is 3. Passing that bitmask as the enum direction shifts the meaning of every non-zero value. An ORIG-only zone passes 1 and is tested as REPLY, while REPL-only and default zones pass 2 or 3 and test bits beyond the valid direction range. In those cases nf_ct_zone_id() can fall back to NF_CT_DEFAULT_ZONE_ID instead of using the real zone id, so different zones can be treated as equal and dedup collapses to tuple equality alone. nf_conncount stores and compares the original-direction tuple for a connection. If an skb already has an attached conntrack entry, get_ct_or_tuple_from_skb() explicitly copies ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, regardless of the packet's ctinfo. Therefore the zone comparison in the tuple dedup path must use IP_CT_DIR_ORIGINAL as well; the zone d
CVE-2026-72247
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-2026-72247
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": [
{
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"version": "21ba8847f857028dc83a0f341e16ecc616e34740",
"lessThan": "82fc35e0da9a91db9a034f8311f18f77a599ae3f",
"versionType": "git"
},
{
"status": "affected",
"version": "21ba8847f857028dc83a0f341e16ecc616e34740",
"lessThan": "78b5d6dbc860776161f9e9206b06ff8a01f531ab",
"versionType": "git"
},
{
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"lessThan": "4f30a89c0ed2418719a1144881c2635b940b543d",
"versionType": "git"
},
{
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"lessThan": "7bdc3c0985ecf17b957811fedcc684acdf698acc",
"versionType": "git"
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{
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"lessThan": "35a56e2a46b90e6bd4ca816b80e9cb8d20dfc3ce",
"versionType": "git"
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{
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"lessThan": "3cd9a5792cbea81139c24320986dd0db69e9b5d0",
"versionType": "git"
},
{
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"lessThan": "6ff07ac5405bea4d4ead3559fc123f987576424a",
"versionType": "git"
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{
"status": "affected",
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"lessThan": "f62c41b4910e65da396ec9a8c40c1fe7fe82e449",
"versionType": "git"
},
{
"status": "affected",
"version": "525e1dffed8711973f77412729621098a95238e5",
"versionType": "git"
},
{
"status": "affected",
"version": "75af3d78168e654a5cd8bbc4c774f97be836165f",
"versionType": "git"
},
{
"status": "affected",
"version": "4.14.92",
"lessThan": "4.15",
"versionType": "semver"
}
],
"programFiles": [
"net/netfilter/nf_conncount.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
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"version": "4.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.18",
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},
{
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"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/netfilter/nf_conncount.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-72247
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #32993 · Revision 1
- Added to Heist Feed
- Publisher date