Vulnerability-Lookup

GHSA-FM5M-5CR7-5Q35

Vulnerability from github – Published: 2026-02-04 18:30 – Updated: 2026-02-04 18:30

Details

In the Linux kernel, the following vulnerability has been resolved:

l2tp: Fix memleak in l2tp_udp_encap_recv().

syzbot reported memleak of struct l2tp_session, l2tp_tunnel, sock, etc. [0]

The cited commit moved down the validation of the protocol version in l2tp_udp_encap_recv().

The new place requires an extra error handling to avoid the memleak.

Let's call l2tp_session_put() there.

[0]: BUG: memory leak unreferenced object 0xffff88810a290200 (size 512): comm "syz.0.17", pid 6086, jiffies 4294944299 hex dump (first 32 bytes): 7d eb 04 0c 00 00 00 00 01 00 00 00 00 00 00 00 }............... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc babb6a4f): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4958 [inline] slab_alloc_node mm/slub.c:5263 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x3e0/0x660 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] l2tp_session_create+0x3a/0x3b0 net/l2tp/l2tp_core.c:1778 pppol2tp_connect+0x48b/0x920 net/l2tp/l2tp_ppp.c:755 __sys_connect_file+0x7a/0xb0 net/socket.c:2089 __sys_connect+0xde/0x110 net/socket.c:2108 __do_sys_connect net/socket.c:2114 [inline] __se_sys_connect net/socket.c:2111 [inline] __x64_sys_connect+0x1c/0x30 net/socket.c:2111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

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{
  "affected": [],
  "aliases": [
    "CVE-2026-23072"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-02-04T17:16:17Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nl2tp: Fix memleak in l2tp_udp_encap_recv().\n\nsyzbot reported memleak of struct l2tp_session, l2tp_tunnel,\nsock, etc. [0]\n\nThe cited commit moved down the validation of the protocol\nversion in l2tp_udp_encap_recv().\n\nThe new place requires an extra error handling to avoid the\nmemleak.\n\nLet\u0027s call l2tp_session_put() there.\n\n[0]:\nBUG: memory leak\nunreferenced object 0xffff88810a290200 (size 512):\n  comm \"syz.0.17\", pid 6086, jiffies 4294944299\n  hex dump (first 32 bytes):\n    7d eb 04 0c 00 00 00 00 01 00 00 00 00 00 00 00  }...............\n    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n  backtrace (crc babb6a4f):\n    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]\n    slab_post_alloc_hook mm/slub.c:4958 [inline]\n    slab_alloc_node mm/slub.c:5263 [inline]\n    __do_kmalloc_node mm/slub.c:5656 [inline]\n    __kmalloc_noprof+0x3e0/0x660 mm/slub.c:5669\n    kmalloc_noprof include/linux/slab.h:961 [inline]\n    kzalloc_noprof include/linux/slab.h:1094 [inline]\n    l2tp_session_create+0x3a/0x3b0 net/l2tp/l2tp_core.c:1778\n    pppol2tp_connect+0x48b/0x920 net/l2tp/l2tp_ppp.c:755\n    __sys_connect_file+0x7a/0xb0 net/socket.c:2089\n    __sys_connect+0xde/0x110 net/socket.c:2108\n    __do_sys_connect net/socket.c:2114 [inline]\n    __se_sys_connect net/socket.c:2111 [inline]\n    __x64_sys_connect+0x1c/0x30 net/socket.c:2111\n    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n    do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94\n    entry_SYSCALL_64_after_hwframe+0x77/0x7f",
  "id": "GHSA-fm5m-5cr7-5q35",
  "modified": "2026-02-04T18:30:43Z",
  "published": "2026-02-04T18:30:43Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23072"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4d10edfd1475b69dbd4c47f34b61a3772ece83ca"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5cd158a88eef34e7b100cd9b963873d3b4e41b35"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d4ce79e6dce2a4a49eebceea7b4caf5dc0f0ef3d"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-23072 (GCVE-0-2026-23072)

Vulnerability from cvelistv5 – Published: 2026-02-04 16:07 – Updated: 2026-02-09 08:38

Title

l2tp: Fix memleak in l2tp_udp_encap_recv().

Summary

In the Linux kernel, the following vulnerability has been resolved: l2tp: Fix memleak in l2tp_udp_encap_recv(). syzbot reported memleak of struct l2tp_session, l2tp_tunnel, sock, etc. [0] The cited commit moved down the validation of the protocol version in l2tp_udp_encap_recv(). The new place requires an extra error handling to avoid the memleak. Let's call l2tp_session_put() there. [0]: BUG: memory leak unreferenced object 0xffff88810a290200 (size 512): comm "syz.0.17", pid 6086, jiffies 4294944299 hex dump (first 32 bytes): 7d eb 04 0c 00 00 00 00 01 00 00 00 00 00 00 00 }............... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc babb6a4f): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4958 [inline] slab_alloc_node mm/slub.c:5263 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x3e0/0x660 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] l2tp_session_create+0x3a/0x3b0 net/l2tp/l2tp_core.c:1778 pppol2tp_connect+0x48b/0x920 net/l2tp/l2tp_ppp.c:755 __sys_connect_file+0x7a/0xb0 net/socket.c:2089 __sys_connect+0xde/0x110 net/socket.c:2108 __do_sys_connect net/socket.c:2114 [inline] __se_sys_connect net/socket.c:2111 [inline] __x64_sys_connect+0x1c/0x30 net/socket.c:2111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/5cd158a88eef34e7b…
	https://git.kernel.org/stable/c/d4ce79e6dce2a4a49…
	https://git.kernel.org/stable/c/4d10edfd1475b69db…

Impacted products

Vendor

Product

Version

Linux

Affected: 364798056f518b0bf2f17cd9eaf0dd4e856d7393 , < 5cd158a88eef34e7b100cd9b963873d3b4e41b35 (git)
Affected: 364798056f518b0bf2f17cd9eaf0dd4e856d7393 , < d4ce79e6dce2a4a49eebceea7b4caf5dc0f0ef3d (git)
Affected: 364798056f518b0bf2f17cd9eaf0dd4e856d7393 , < 4d10edfd1475b69dbd4c47f34b61a3772ece83ca (git)

Linux

Affected: 6.10
Unaffected: 0 , < 6.10 (semver)
Unaffected: 6.12.68 , ≤ 6.12.* (semver)
Unaffected: 6.18.8 , ≤ 6.18.* (semver)
Unaffected: 6.19 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/l2tp/l2tp_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5cd158a88eef34e7b100cd9b963873d3b4e41b35",
              "status": "affected",
              "version": "364798056f518b0bf2f17cd9eaf0dd4e856d7393",
              "versionType": "git"
            },
            {
              "lessThan": "d4ce79e6dce2a4a49eebceea7b4caf5dc0f0ef3d",
              "status": "affected",
              "version": "364798056f518b0bf2f17cd9eaf0dd4e856d7393",
              "versionType": "git"
            },
            {
              "lessThan": "4d10edfd1475b69dbd4c47f34b61a3772ece83ca",
              "status": "affected",
              "version": "364798056f518b0bf2f17cd9eaf0dd4e856d7393",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/l2tp/l2tp_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.10"
            },
            {
              "lessThan": "6.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.68",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.19",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.68",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.8",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nl2tp: Fix memleak in l2tp_udp_encap_recv().\n\nsyzbot reported memleak of struct l2tp_session, l2tp_tunnel,\nsock, etc. [0]\n\nThe cited commit moved down the validation of the protocol\nversion in l2tp_udp_encap_recv().\n\nThe new place requires an extra error handling to avoid the\nmemleak.\n\nLet\u0027s call l2tp_session_put() there.\n\n[0]:\nBUG: memory leak\nunreferenced object 0xffff88810a290200 (size 512):\n  comm \"syz.0.17\", pid 6086, jiffies 4294944299\n  hex dump (first 32 bytes):\n    7d eb 04 0c 00 00 00 00 01 00 00 00 00 00 00 00  }...............\n    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n  backtrace (crc babb6a4f):\n    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]\n    slab_post_alloc_hook mm/slub.c:4958 [inline]\n    slab_alloc_node mm/slub.c:5263 [inline]\n    __do_kmalloc_node mm/slub.c:5656 [inline]\n    __kmalloc_noprof+0x3e0/0x660 mm/slub.c:5669\n    kmalloc_noprof include/linux/slab.h:961 [inline]\n    kzalloc_noprof include/linux/slab.h:1094 [inline]\n    l2tp_session_create+0x3a/0x3b0 net/l2tp/l2tp_core.c:1778\n    pppol2tp_connect+0x48b/0x920 net/l2tp/l2tp_ppp.c:755\n    __sys_connect_file+0x7a/0xb0 net/socket.c:2089\n    __sys_connect+0xde/0x110 net/socket.c:2108\n    __do_sys_connect net/socket.c:2114 [inline]\n    __se_sys_connect net/socket.c:2111 [inline]\n    __x64_sys_connect+0x1c/0x30 net/socket.c:2111\n    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n    do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94\n    entry_SYSCALL_64_after_hwframe+0x77/0x7f"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-09T08:38:11.460Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/5cd158a88eef34e7b100cd9b963873d3b4e41b35"
        },
        {
          "url": "https://git.kernel.org/stable/c/d4ce79e6dce2a4a49eebceea7b4caf5dc0f0ef3d"
        },
        {
          "url": "https://git.kernel.org/stable/c/4d10edfd1475b69dbd4c47f34b61a3772ece83ca"
        }
      ],
      "title": "l2tp: Fix memleak in l2tp_udp_encap_recv().",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23072",
    "datePublished": "2026-02-04T16:07:52.790Z",
    "dateReserved": "2026-01-13T15:37:45.957Z",
    "dateUpdated": "2026-02-09T08:38:11.460Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-FM5M-5CR7-5Q35

CVE-2026-23072 (GCVE-0-2026-23072)

Tags

Sightings

Nomenclature