mptcp: pm: in-kernel: always mark signal+subflow endp as used
In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: in-kernel: always mark signal+subflow endp as used Syzkaller managed to find a combination of actions that was generating this warning: msk->pm.local_addr_used == 0 WARNING: net/mptcp/pm_kernel.c:1071 at __mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline], CPU#1: syz.2.17/961 WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline], CPU#1: syz.2.17/961 WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210, CPU#1: syz.2.17/961 Modules linked in: CPU: 1 UID: 0 PID: 961 Comm: syz.2.17 Not tainted 6.19.0-08368-gfafda3b4b06b #22 PREEMPT(full) Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.17.0-debian-1.17.0-1build1 04/01/2014 RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline] RIP: 0010:mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline] RIP: 0010:mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210 Code: 89 c5 e8 46 30 6f fe e9 21 fd ff ff 49 83 ed 80 e8 38 30 6f fe 4c 89 ef be 03 00 00 00 e8 db 49 df fe eb ac e8 24 30 6f fe 90 <0f> 0b 90 e9 1d ff ff ff e8 16 30 6f fe eb 05 e8 0f 30 6f fe e8 9a RSP: 0018:ffffc90001663880 EFLAGS: 00010293 RAX: ffffffff82de1a6c RBX: 0000000000000000 RCX: ffff88800722b500 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880158b22
- Products
- Kernel
- Affected versions
- Not specified
- Fixed versions
- 6.1.167, 6.12.78, 6.18.17, 6.19.7, 6.6.130
- CVEs
- CVE-2026-23321
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 5 Nov 2026, 17:45 UTC · Revision 1
Source evidence
mptcp: pm: in-kernel: always mark signal+subflow endp as used
core-osv · Original sourcePublished 25 Mar 2026, 10:27 UTC
In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: in-kernel: always mark signal+subflow endp as used Syzkaller managed to find a combination of actions that was generating this warning: msk->pm.local_addr_used == 0 WARNING: net/mptcp/pm_kernel.c:1071 at __mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline], CPU#1: syz.2.17/961 WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline], CPU#1: syz.2.17/961 WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210, CPU#1: syz.2.17/961 Modules linked in: CPU: 1 UID: 0 PID: 961 Comm: syz.2.17 Not tainted 6.19.0-08368-gfafda3b4b06b #22 PREEMPT(full) Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.17.0-debian-1.17.0-1build1 04/01/2014 RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline] RIP: 0010:mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline] RIP: 0010:mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210 Code: 89 c5 e8 46 30 6f fe e9 21 fd ff ff 49 83 ed 80 e8 38 30 6f fe 4c 89 ef be 03 00 00 00 e8 db 49 df fe eb ac e8 24 30 6f fe 90 <0f> 0b 90 e9 1d ff ff ff e8 16 30 6f fe eb 05 e8 0f 30 6f fe e8 9a RSP: 0018:ffffc90001663880 EFLAGS: 00010293 RAX: ffffffff82de1a6c RBX: 0000000000000000 RCX: ffff88800722b500 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880158b22
osv:CVE-2026-23321
Kernel
Fixed versions: 6.1.167, 6.6.130, 6.12.78, 6.18.17, 6.19.7
Complete source record
{
"id": "d1fe055d24c3b2014bd8aa2370e46b7c7dac82a9941de5324944984a514a041a",
"url": "https://osv.dev/vulnerability/CVE-2026-23321",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "mptcp: pm: in-kernel: always mark signal+subflow endp as used",
"summary": "In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: in-kernel: always mark signal+subflow endp as used Syzkaller managed to find a combination of actions that was generating this warning: msk->pm.local_addr_used == 0 WARNING: net/mptcp/pm_kernel.c:1071 at __mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline], CPU#1: syz.2.17/961 WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline], CPU#1: syz.2.17/961 WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210, CPU#1: syz.2.17/961 Modules linked in: CPU: 1 UID: 0 PID: 961 Comm: syz.2.17 Not tainted 6.19.0-08368-gfafda3b4b06b #22 PREEMPT(full) Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.17.0-debian-1.17.0-1build1 04/01/2014 RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline] RIP: 0010:mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline] RIP: 0010:mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210 Code: 89 c5 e8 46 30 6f fe e9 21 fd ff ff 49 83 ed 80 e8 38 30 6f fe 4c 89 ef be 03 00 00 00 e8 db 49 df fe eb ac e8 24 30 6f fe 90 <0f> 0b 90 e9 1d ff ff ff e8 16 30 6f fe eb 05 e8 0f 30 6f fe e8 9a RSP: 0018:ffffc90001663880 EFLAGS: 00010293 RAX: ffffffff82de1a6c RBX: 0000000000000000 RCX: ffff88800722b500 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880158b22",
"evidence": "osv:CVE-2026-23321",
"products": [
{
"name": {
"value": "Kernel",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.1.167",
"evidence": "/affected/1/ranges"
},
{
"value": "6.6.130",
"evidence": "/affected/1/ranges"
},
{
"value": "6.12.78",
"evidence": "/affected/1/ranges"
},
{
"value": "6.18.17",
"evidence": "/affected/1/ranges"
},
{
"value": "6.19.7",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "CVE-2026-23321",
"aliases": [
"CVE-2026-23321"
],
"affected": [
{
"ranges": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "d93cf38fad9f66397093432b8917971a92ee0146"
},
{
"fixed": "c5c877e140e5f46023a74a51e577ce5edd0a4be7"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "64815ba15880ce5f99df075fa4104fef170ac7e5"
},
{
"fixed": "05799c2f1ca5eb13d65764dda688d02021b65e06"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "85df533a787bf07bf4367ce2a02b822ff1fba1a3"
},
{
"fixed": "67f34ab318807989b57dfdb0f79e2d4e57018290"
},
{
"fixed": "a64aa7db39392add5be09dffaedbf1f0ce5554df"
},
{
"fixed": "198824ccfa64ffebd918bf99c939bd8170a4a4d8"
},
{
"fixed": "579a752464a64cb5f9139102f0e6b90a1f595ceb"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.1.106"
},
{
"fixed": "6.1.167"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.6.46"
},
{
"fixed": "6.6.130"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.10.5"
},
{
"fixed": "6.11"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "0f21cc29bc13e86512621727a4388c8a7ad2716b"
}
]
}
],
"versions": [
"v6.1.166",
"v6.1.165",
"v6.1.164",
"v6.1.163",
"v6.1.162",
"v6.1.161",
"v6.1.160",
"v6.1.159",
"v6.1.158",
"v6.1.157",
"v6.1.156",
"v6.1.155",
"v6.1.154",
"v6.1.153",
"v6.1.152",
"v6.1.151",
"v6.1.150",
"v6.1.149",
"v6.1.148",
"v6.1.147",
"v6.1.146",
"v6.1.145",
"v6.1.144",
"v6.1.143",
"v6.1.142",
"v6.1.141",
"v6.1.140",
"v6.1.139",
"v6.1.138",
"v6.1.137",
"v6.1.136",
"v6.1.135",
"v6.1.134",
"v6.1.133",
"v6.1.132",
"v6.1.131",
"v6.1.130",
"v6.1.129",
"v6.1.128",
"v6.1.127",
"v6.1.126",
"v6.1.125",
"v6.1.124",
"v6.1.123",
"v6.1.122",
"v6.1.121",
"v6.1.120",
"v6.1.119",
"v6.1.118",
"v6.1.117",
"v6.1.116",
"v6.1.115",
"v6.1.114",
"v6.1.113",
"v6.1.112",
"v6.1.111",
"v6.1.110",
"v6.1.109",
"v6.1.108",
"v6.1.107",
"v6.1.106",
"v6.6.129",
"v6.6.128",
"v6.6.127",
"v6.6.126",
"v6.6.125",
"v6.6.124",
"v6.6.123",
"v6.6.122",
"v6.6.121",
"v6.6.120",
"v6.6.119",
"v6.6.118",
"v6.6.117",
"v6.6.116",
"v6.6.115",
"v6.6.114",
"v6.6.113",
"v6.6.112",
"v6.6.111",
"v6.6.110",
"v6.6.109",
"v6.6.108",
"v6.6.107",
"v6.6.106",
"v6.6.105",
"v6.6.104",
"v6.6.103",
"v6.6.102",
"v6.6.101",
"v6.6.100",
"v6.6.99",
"v6.6.98",
"v6.6.97",
"v6.6.96",
"v6.6.95",
"v6.6.94",
"v6.6.93",
"v6.6.92",
"v6.6.91",
"v6.6.90",
"v6.6.89",
"v6.6.88",
"v6.6.87",
"v6.6.86",
"v6.6.85",
"v6.6.84",
"v6.6.83",
"v6.6.82",
"v6.6.81",
"v6.6.80",
"v6.6.79",
"v6.6.78",
"v6.6.77",
"v6.6.76",
"v6.6.75",
"v6.6.74",
"v6.6.73",
"v6.6.72",
"v6.6.71",
"v6.6.70",
"v6.6.69",
"v6.6.68",
"v6.6.67",
"v6.6.66",
"v6.6.65",
"v6.6.64",
"v6.6.63",
"v6.6.62",
"v6.6.61",
"v6.6.60",
"v6.6.59",
"v6.6.58",
"v6.6.57",
"v6.6.56",
"v6.6.55",
"v6.6.54",
"v6.6.53",
"v6.6.52",
"v6.6.51",
"v6.6.50",
"v6.6.49",
"v6.6.48",
"v6.6.47",
"v6.6.46",
"v6.10.14",
"v6.10.13",
"v6.10.12",
"v6.10.11",
"v6.10.10",
"v6.10.9",
"v6.10.8",
"v6.10.7",
"v6.10.6",
"v6.10.5"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23321.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.1.167"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.2.0"
},
{
"fixed": "6.6.130"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.7.0"
},
{
"fixed": "6.12.78"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.11.0"
},
{
"fixed": "6.18.17"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.13.0"
},
{
"fixed": "6.19.7"
}
]
}
],
"package": {
"name": "Kernel",
"ecosystem": "Linux"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23321.json"
}
}
],
"modified": "2026-10-28T02:30:44.994644674Z",
"provider": "osv",
"references": [
"https://cert-portal.siemens.com/productcert/html/ssa-019113.html",
"https://cert-portal.siemens.com/productcert/html/ssa-082556.html",
"https://cert-portal.siemens.com/productcert/html/ssa-457936.html",
"https://cert-portal.siemens.com/productcert/html/ssa-784472.html",
"https://git.kernel.org/stable/c/05799c2f1ca5eb13d65764dda688d02021b65e06",
"https://git.kernel.org/stable/c/198824ccfa64ffebd918bf99c939bd8170a4a4d8",
"https://git.kernel.org/stable/c/579a752464a64cb5f9139102f0e6b90a1f595ceb",
"https://git.kernel.org/stable/c/67f34ab318807989b57dfdb0f79e2d4e57018290",
"https://git.kernel.org/stable/c/a64aa7db39392add5be09dffaedbf1f0ce5554df",
"https://git.kernel.org/stable/c/c5c877e140e5f46023a74a51e577ce5edd0a4be7",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23321.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-23321",
"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
],
"provider_metadata": {
"cna_assigner": "Linux",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23321.json"
}
},
"related_cves": [
{
"value": "CVE-2026-23321",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 512571,
"published_at": "2026-03-25T10:27:15.125+00:00"
}