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

Vulnerability from cvelistv5 – Published: 2026-02-04 16:07 – Updated: 2026-05-11 21:59
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": {
    "cna": {
      "affected": [
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          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/l2tp/l2tp_core.c"
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          "vendor": "Linux",
          "versions": [
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              "version": "6.18.8",
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      "cpeApplicability": [
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          "nodes": [
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              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
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                }
              ],
              "negate": false,
              "operator": "OR"
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      ],
      "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": "2026-05-11T21:59:27.431Z",
        "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": {
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  "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": "2026-05-11T21:59:27.431Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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