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

Vulnerability from cvelistv5 – Published: 2026-02-04 16:07 – Updated: 2026-02-09 08:38
VLAI?
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
References
Impacted products
Vendor Product Version
Linux Linux Affected: 364798056f518b0bf2f17cd9eaf0dd4e856d7393 , < 5cd158a88eef34e7b100cd9b963873d3b4e41b35 (git)
Affected: 364798056f518b0bf2f17cd9eaf0dd4e856d7393 , < d4ce79e6dce2a4a49eebceea7b4caf5dc0f0ef3d (git)
Affected: 364798056f518b0bf2f17cd9eaf0dd4e856d7393 , < 4d10edfd1475b69dbd4c47f34b61a3772ece83ca (git)
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    Linux 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": {
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          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/l2tp/l2tp_core.c"
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              "version": "6.18.8",
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          "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"
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        "dateUpdated": "2026-02-09T08:38:11.460Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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        {
          "url": "https://git.kernel.org/stable/c/4d10edfd1475b69dbd4c47f34b61a3772ece83ca"
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      ],
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    "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"
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  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-23072\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-02-04T17:16:17.923\",\"lastModified\":\"2026-03-18T17:17:52.883\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"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\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\\n\\nl2tp: Solucionar fuga de memoria en l2tp_udp_encap_recv().\\n\\nsyzbot inform\u00f3 una fuga de memoria de struct l2tp_session, l2tp_tunnel, sock, etc. [0]\\n\\nEl commit citado movi\u00f3 hacia abajo la validaci\u00f3n de la versi\u00f3n del protocolo en l2tp_udp_encap_recv().\\n\\nEl nuevo lugar requiere un manejo de errores adicional para evitar la fuga de memoria.\\n\\nLlamemos a l2tp_session_put() all\u00ed.\\n\\n[0]:\\nERROR: fuga de memoria\\nobjeto sin referencia 0xffff88810a290200 (tama\u00f1o 512):\\n  comm \u0027syz.0.17\u0027, pid 6086, jiffies 4294944299\\n  volcado hexadecimal (primeros 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  rastreo de pila (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\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-401\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.10\",\"versionEndExcluding\":\"6.12.68\",\"matchCriteriaId\":\"B360F4B3-2812-43A4-9C53-C15FABD0EBFB\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.18.8\",\"matchCriteriaId\":\"E65C6E79-7EBE-4C77-93F0-818CF5B38F4E\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*\",\"matchCriteriaId\":\"17B67AA7-40D6-4AFA-8459-F200F3D7CFD1\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*\",\"matchCriteriaId\":\"C47E4CC9-C826-4FA9-B014-7FE3D9B318B2\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*\",\"matchCriteriaId\":\"F71D92C0-C023-48BD-B3B6-70B638EEE298\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*\",\"matchCriteriaId\":\"13580667-0A98-40CC-B29F-D12790B91BDB\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*\",\"matchCriteriaId\":\"CAD1FED7-CF48-47BF-AC7D-7B6FA3C065FC\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*\",\"matchCriteriaId\":\"3EF854A1-ABB1-4E93-BE9A-44569EC76C0D\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/4d10edfd1475b69dbd4c47f34b61a3772ece83ca\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/5cd158a88eef34e7b100cd9b963873d3b4e41b35\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/d4ce79e6dce2a4a49eebceea7b4caf5dc0f0ef3d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}"
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}


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Sightings

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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.