ipv4: fib: bound automatic table ID allocation
In the Linux kernel, the following vulnerability has been resolved: ipv4: fib: bound automatic table ID allocation fib_empty_table() probes every table ID from 1 until it finds a free one. IPv4 tables are stored in a 256-bucket hash table, so a dense set of IDs makes each probe walk a growing hash chain while RTNL is held. Automatic table assignment ("ip rule ... table 0") is an IPv4-only legacy path. Bound the automatically allocated ID to 4096 so the RTNL hold stays bounded, without changing lookups of explicitly specified table IDs. This changes user-visible behavior. A table-0 rule previously received the lowest free ID in 1..RT_TABLE_MAX (0xFFFFFFFF). After this patch the search stops at 4096 and the rule add fails with ENOBUFS if that range is fully occupied. Explicit table IDs above 4096 remain usable. The automatic path is unused in practice: it is IPv4-only, not documented by ip-rule, uncovered by kernel selftests, and both NetworkManager and systemd refuse table 0.
CVE-2026-97598
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-2026-97598
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": "b801f54917b7c6e8540f877ee562cd0725e62ebd",
"lessThan": "999bc00588cb305ab25065e8a8ac31da7465301c",
"versionType": "git"
},
{
"status": "affected",
"version": "b801f54917b7c6e8540f877ee562cd0725e62ebd",
"lessThan": "f1f2da33eaab54b4d5cdea6d70befb2e2fb49cb6",
"versionType": "git"
},
{
"status": "affected",
"version": "b801f54917b7c6e8540f877ee562cd0725e62ebd",
"lessThan": "125890702ef4417cd0ffac2e448c0cd4fbf0ac45",
"versionType": "git"
},
{
"status": "affected",
"version": "b801f54917b7c6e8540f877ee562cd0725e62ebd",
"lessThan": "3080f9e653d8c057d5652db5ced8137f81b3fcbd",
"versionType": "git"
},
{
"status": "affected",
"version": "b801f54917b7c6e8540f877ee562cd0725e62ebd",
"lessThan": "bc8d01d856db106f284b19961af6112e10c3e3b4",
"versionType": "git"
},
{
"status": "affected",
"version": "b801f54917b7c6e8540f877ee562cd0725e62ebd",
"lessThan": "fe9a906d2bff2d2707bafd6353b5e032a42aeb35",
"versionType": "git"
},
{
"status": "affected",
"version": "b801f54917b7c6e8540f877ee562cd0725e62ebd",
"lessThan": "2c29c053a6627dc4f12fcfe6b4860bcd9e5d7503",
"versionType": "git"
},
{
"status": "affected",
"version": "b801f54917b7c6e8540f877ee562cd0725e62ebd",
"lessThan": "efdfb1e27a3328085b79540dfe781d537b576ea1",
"versionType": "git"
}
],
"programFiles": [
"net/ipv4/fib_rules.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.19"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.19",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.271",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/ipv4/fib_rules.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-97598
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38039 · Revision 1
- Added to Heist Feed
- Publisher date