mptcp: options: fix uninit-value in mptcp_write_data_fin
In the Linux kernel, the following vulnerability has been resolved: mptcp: options: fix uninit-value in mptcp_write_data_fin When sending a DATA_FIN without data, and because the DATA_FIN occupies 1 octet of the connection-level sequence space [1], it is then required to add a DSS mapping with specific values. If the checksum has been negotiated, it also needs to be computed, and included in the outgoing packet, and thus the initial csum data needs to be reset to 0 as well. This is no longer the case since commit cfcceb7a39fc ("tcp: shrink per-packet memset in __tcp_transmit_skb()"), because the whole ext_copy structure is no longer zeroed by default. This seems to be the only case where use_map is changed and set afterwards, so initialising the csum field only in this case, along with other fields for this specific case.
CVE-2026-98438
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-2026-98438
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": "cfcceb7a39fc10a6f896af8229bf81d96acb22cc",
"lessThan": "9a682067dd7b9dce6b94a0a05661dcc921446402",
"versionType": "git"
},
{
"status": "affected",
"version": "cfcceb7a39fc10a6f896af8229bf81d96acb22cc",
"lessThan": "b110f1dd6cb6a9930503354a01a315e0a821eaa7",
"versionType": "git"
}
],
"programFiles": [
"net/mptcp/options.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "7.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "7.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/mptcp/options.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98438
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38500 · Revision 1
- Added to Heist Feed
- Publisher date