mptcp: pm: only set fullmesh for subflow endp
In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: only set fullmesh for subflow endp With the in-kernel path-manager, it is possible to change the 'fullmesh' flag. The code in mptcp_pm_nl_fullmesh() expects to change it only on 'subflow' endpoints, to recreate more or less subflows using the linked address. Unfortunately, the set_flags() hook was a bit more permissive, and allowed 'implicit' endpoints to get the 'fullmesh' flag while it is not allowed before. That's what syzbot found, triggering the following warning: WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 __mark_subflow_endp_available net/mptcp/pm_netlink.c:1496 [inline] WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_pm_nl_fullmesh net/mptcp/pm_netlink.c:1980 [inline] WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_nl_set_flags net/mptcp/pm_netlink.c:2003 [inline] WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_pm_nl_set_flags+0x974/0xdc0 net/mptcp/pm_netlink.c:2064 Modules linked in: CPU: 0 UID: 0 PID: 6499 Comm: syz.1.413 Not tainted 6.13.0-rc5-syzkaller-00172-gd1bf27c4e176 #0 Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_netlink.c:1496 [inline] RIP: 0010:mptcp_pm_nl_fullmesh net/mptcp/pm_netlink.c:1980 [inline] RIP: 0010:mptcp_nl_set_flags net/mptcp/pm_netlink.c:2003 [inline] RIP: 0010:mptcp_pm_nl_set_flags+0x974/0xdc0 net/mptcp/pm_netlink.c:
CVE-2025-21706
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-2025-21706
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": "73c762c1f07dacba4fd1cefd15e24b419d42320d",
"lessThan": "22b0734c9401a74ed4ebd9e8ef0da33e493852eb",
"versionType": "git"
},
{
"status": "affected",
"version": "73c762c1f07dacba4fd1cefd15e24b419d42320d",
"lessThan": "de3b8d41d2547452c4cafb146d003fa4689fbaf2",
"versionType": "git"
},
{
"status": "affected",
"version": "73c762c1f07dacba4fd1cefd15e24b419d42320d",
"lessThan": "8ac344cbd84fda75e05e1f445f7f8fb24dc175e1",
"versionType": "git"
},
{
"status": "affected",
"version": "73c762c1f07dacba4fd1cefd15e24b419d42320d",
"lessThan": "9e3d61620a3cd033319553b980ff3a350adbe1bc",
"versionType": "git"
},
{
"status": "affected",
"version": "73c762c1f07dacba4fd1cefd15e24b419d42320d",
"lessThan": "1bb0d1348546ad059f55c93def34e67cb2a034a6",
"versionType": "git"
}
],
"programFiles": [
"net/mptcp/pm_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": "5.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.129",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.78",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.13",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.13.2",
"versionType": "semver",
"lessThanOrEqual": "6.13.*"
},
{
"status": "unaffected",
"version": "6.14",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/mptcp/pm_netlink.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-21706
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #26914 · Revision 1
- Added to Heist Feed
- Publisher date