ipvs: reset full ip_vs_seq structs in ip_vs_conn_new
In the Linux kernel, the following vulnerability has been resolved: ipvs: reset full ip_vs_seq structs in ip_vs_conn_new Commit 9a05475cebdd ("ipvs: avoid kmem_cache_zalloc in ip_vs_conn_new") changed ip_vs_conn_new() to allocate an ip_vs_conn object with kmem_cache_alloc(). The function then initializes many fields explicitly, but only resets in_seq.delta and out_seq.delta in the two struct ip_vs_seq members. That leaves init_seq and previous_delta uninitialized. This is normally harmless while the corresponding IP_VS_CONN_F_IN_SEQ or IP_VS_CONN_F_OUT_SEQ flag is clear. For connections learned from a sync message, however, ip_vs_proc_conn() preserves those flags from IP_VS_CONN_F_BACKUP_MASK and passes opt=NULL when the message omits IPVS_OPT_SEQ_DATA. In that case the new connection can be hashed with SEQ flags set but with the rest of in_seq/out_seq still containing stale slab data. When a packet for such a connection is later handled by an IPVS application helper, vs_fix_seq() and vs_fix_ack_seq() use previous_delta and init_seq to rewrite TCP sequence numbers. A malformed sync message can therefore make forwarded packets carry stale slab bytes in their TCP seq/ack numbers, and can also corrupt the forwarded TCP flow. Reset both struct ip_vs_seq members completely before publishing the connection. This matches the existing "reset struct ip_vs_seq" comment and keeps the sequence-adjustment gates inactive unless valid sequence data is installed later.
CVE-2026-72020
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-2026-72020
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": "9a05475cebdd6341884b5901e53870be26e65158",
"lessThan": "3bf9a260188b2a5449cbddc032a749ab433fe328",
"versionType": "git"
},
{
"status": "affected",
"version": "9a05475cebdd6341884b5901e53870be26e65158",
"lessThan": "6378c5cb360eb1750f88839d7c3613ea92ac1816",
"versionType": "git"
},
{
"status": "affected",
"version": "9a05475cebdd6341884b5901e53870be26e65158",
"lessThan": "32c299e28b8eea6cbbd23b97dc61401e9ef9c445",
"versionType": "git"
},
{
"status": "affected",
"version": "9a05475cebdd6341884b5901e53870be26e65158",
"lessThan": "9e36602cbec552286f7e691cfd366525c565ee74",
"versionType": "git"
},
{
"status": "affected",
"version": "9a05475cebdd6341884b5901e53870be26e65158",
"lessThan": "d0eed7177e822cab83141e5c44b2aa345c7fd379",
"versionType": "git"
},
{
"status": "affected",
"version": "9a05475cebdd6341884b5901e53870be26e65158",
"lessThan": "83fb4c2c5344f02eac929f66de3c9d1adfcde04c",
"versionType": "git"
},
{
"status": "affected",
"version": "9a05475cebdd6341884b5901e53870be26e65158",
"lessThan": "6335ab62d5fc9ed875279238233fba3462c168f5",
"versionType": "git"
},
{
"status": "affected",
"version": "9a05475cebdd6341884b5901e53870be26e65158",
"lessThan": "2975324d164c552b028632f107b567302863b7f6",
"versionType": "git"
}
],
"programFiles": [
"net/netfilter/ipvs/ip_vs_conn.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.10"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.10",
"versionType": "semver"
},
{
"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/ipvs/ip_vs_conn.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-72020
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #41839 · Revision 1
- Added to Heist Feed
- Publisher date