CVE-2023-53490
In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix disconnect vs accept race
Despite commit 0ad529d9fd2b ("mptcp: fix possible divide by zero in recvmsg()"), the mptcp protocol is still prone to a race between disconnect() (or shutdown) and accept.
The root cause is that the mentioned commit checks the msk-level flag, but mptcp_stream_accept() does acquire the msk-level lock, as it can rely directly on the first subflow lock.
As reported by Christoph than can lead to a race where an msk socket is accepted after that mptcp_subflow_queue_clean() releases the listener socket lock and just before it takes destructive actions leading to the following splat:
Leer descripción completaMostrar menos
Address the issue by temporary removing the pending request socket from the accept queue, so that racing accept() can't touch them.
After depleting the msk - the ssk still exists, as plain TCP sockets, re-insert them into the accept queue, so that later inet_csk_listen_stop() will complete the tcp socket disposal.
Detalles técnicos trazas, registros y código del informe original
BUG: kernel NULL pointer dereference, address: 0000000000000012 PGD 5a4ca067 P4D 5a4ca067 PUD 37d4c067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 2 PID: 10955 Comm: syz-executor.5 Not tainted 6.5.0-rc1-gdc7b257ee5dd #37 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 RIP: 0010:mptcp_stream_accept+0x1ee/0x2f0 include/net/inet_sock.h:330 Code: 0a 09 00 48 8b 1b 4c 39 e3 74 07 e8 bc 7c 7f fe eb a1 e8 b5 7c 7f fe 4c 8b 6c 24 08 eb 05 e8 a9 7c 7f fe 49 8b 85 d8 09 00 00 <0f> b6 40 12 88 44 24 07 0f b6 6c 24 07 bf 07 00 00 00 89 ee e8 89 RSP: 0018:ffffc90000d07dc0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff888037e8d020 RCX: ffff88803b093300 RDX: 0000000000000000 RSI: ffffffff833822c5 RDI: ffffffff8333896a RBP: 0000607f82031520 R08: ffff88803b093300 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000003e83 R12: ffff888037e8d020 R13: ffff888037e8c680 R14: ffff888009af7900 R15: ffff888009af6880 FS: 00007fc26d708640(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000012 CR3: 0000000066bc5001 CR4: 0000000000370ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> do_accept+0x1ae/0x260 net/socket.c:1872 __sys_accept4+0x9b/0x110 net/socket.c:1913 __do_sys_accept4 net/socket.c:1954 [inline] __se_sys_accept4 net/socket.c:1951 [inline] __x64_sys_accept4+0x20/0x30 net/socket.c:1951 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x47/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 4.7
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.12%
- Percentil entre todas las CVEs puntuadas: 2
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-362
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2023-53490",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 4.7,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 1
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "b45d8f5375eda3ddc89fe529b58bb643917bd87b",
"lessThan": "ded9f5551ce5cafa3c41c794428c27a0d0a00542",
"versionType": "git"
},
{
"status": "affected",
"version": "2a6a870e44dd88f1a6a2893c65ef756a9edfb4c7",
"lessThan": "b2b4c84eb7149f34c0f25f17042d095ba5357d68",
"versionType": "git"
},
{
"status": "affected",
"version": "2a6a870e44dd88f1a6a2893c65ef756a9edfb4c7",
"lessThan": "511b90e39250135a7f900f1c3afbce25543018a2",
"versionType": "git"
},
{
"status": "affected",
"version": "64b66601308dae6105fbde964a339462a29c2a73",
"versionType": "git"
},
{
"status": "affected",
"version": "6.1.27",
"lessThan": "6.1.46",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.2.13",
"lessThan": "6.3",
"versionType": "semver"
}
],
"programFiles": [
"net/mptcp/protocol.h",
"net/mptcp/subflow.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.3"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.3",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.46",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.4.11",
"versionType": "semver",
"lessThanOrEqual": "6.4.*"
},
{
"status": "unaffected",
"version": "6.5",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/mptcp/protocol.h",
"net/mptcp/subflow.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-10-01T12:15:52.107",
"references": [
{
"url": "https://git.kernel.org/stable/c/511b90e39250135a7f900f1c3afbce25543018a2",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b2b4c84eb7149f34c0f25f17042d095ba5357d68",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ded9f5551ce5cafa3c41c794428c27a0d0a00542",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-362"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix disconnect vs accept race\n\nDespite commit 0ad529d9fd2b (\"mptcp: fix possible divide by zero in\nrecvmsg()\"), the mptcp protocol is still prone to a race between\ndisconnect() (or shutdown) and accept.\n\nThe root cause is that the mentioned commit checks the msk-level\nflag, but mptcp_stream_accept() does acquire the msk-level lock,\nas it can rely directly on the first subflow lock.\n\nAs reported by Christoph than can lead to a race where an msk\nsocket is accepted after that mptcp_subflow_queue_clean() releases\nthe listener socket lock and just before it takes destructive\nactions leading to the following splat:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000012\nPGD 5a4ca067 P4D 5a4ca067 PUD 37d4c067 PMD 0\nOops: 0000 [#1] PREEMPT SMP\nCPU: 2 PID: 10955 Comm: syz-executor.5 Not tainted 6.5.0-rc1-gdc7b257ee5dd #37\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014\nRIP: 0010:mptcp_stream_accept+0x1ee/0x2f0 include/net/inet_sock.h:330\nCode: 0a 09 00 48 8b 1b 4c 39 e3 74 07 e8 bc 7c 7f fe eb a1 e8 b5 7c 7f fe 4c 8b 6c 24 08 eb 05 e8 a9 7c 7f fe 49 8b 85 d8 09 00 00 <0f> b6 40 12 88 44 24 07 0f b6 6c 24 07 bf 07 00 00 00 89 ee e8 89\nRSP: 0018:ffffc90000d07dc0 EFLAGS: 00010293\nRAX: 0000000000000000 RBX: ffff888037e8d020 RCX: ffff88803b093300\nRDX: 0000000000000000 RSI: ffffffff833822c5 RDI: ffffffff8333896a\nRBP: 0000607f82031520 R08: ffff88803b093300 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000003e83 R12: ffff888037e8d020\nR13: ffff888037e8c680 R14: ffff888009af7900 R15: ffff888009af6880\nFS: 00007fc26d708640(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000000000000012 CR3: 0000000066bc5001 CR4: 0000000000370ee0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n <TASK>\n do_accept+0x1ae/0x260 net/socket.c:1872\n __sys_accept4+0x9b/0x110 net/socket.c:1913\n __do_sys_accept4 net/socket.c:1954 [inline]\n __se_sys_accept4 net/socket.c:1951 [inline]\n __x64_sys_accept4+0x20/0x30 net/socket.c:1951\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x47/0xa0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x6e/0xd8\n\nAddress the issue by temporary removing the pending request socket\nfrom the accept queue, so that racing accept() can't touch them.\n\nAfter depleting the msk - the ssk still exists, as plain TCP sockets,\nre-insert them into the accept queue, so that later inet_csk_listen_stop()\nwill complete the tcp socket disposal."
}
],
"lastModified": "2026-08-04T10:19:08.740",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "D678B754-FB4C-490F-BA8B-8C7ABE9F5FE0",
"versionEndExcluding": "6.1.46",
"versionStartIncluding": "6.1.27"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "2D91BE00-CF2F-446D-8396-5BDEF4F60DA9",
"versionEndExcluding": "6.3",
"versionStartIncluding": "6.2.13"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "5C318D2A-FCC9-4A15-B1E8-94D32BBC5EAA",
"versionEndExcluding": "6.4.11",
"versionStartIncluding": "6.3.1"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.3:-:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "21D6F467-B848-453E-B1A4-BEF940E413A6"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "0B3E6E4D-E24E-4630-B00C-8C9901C597B0"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc2:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E4A01A71-0F09-4DB2-A02F-7EFFBE27C98D"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc3:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "F5608371-157A-4318-8A2E-4104C3467EA1"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc4:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "2226A776-DF8C-49E0-A030-0A7853BB018A"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc5:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "6F15C659-DF06-455A-9765-0E6DE920F29A"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}