{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-23286",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-23286"
  ],
  "published": "2026-03-25T10:28:03Z",
  "summary": "atm: lec: fix null-ptr-deref in lec_arp_clear_vccs",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\natm: lec: fix null-ptr-deref in lec_arp_clear_vccs\n\nsyzkaller reported a null-ptr-deref in lec_arp_clear_vccs().\nThis issue can be easily reproduced using the syzkaller reproducer.\n\nIn the ATM LANE (LAN Emulation) module, the same atm_vcc can be shared by\nmultiple lec_arp_table entries (e.g., via entry->vcc or entry->recv_vcc).\nWhen the underlying VCC is closed, lec_vcc_close() iterates over all\nARP entries and calls lec_arp_clear_vccs() for each matched entry.\n\nFor example, when lec_vcc_close() iterates through the hlists in\npriv->lec_arp_empty_ones or other ARP tables:\n\n1. In the first iteration, for the first matched ARP entry sharing the VCC,\nlec_arp_clear_vccs() frees the associated vpriv (which is vcc->user_back)\nand sets vcc->user_back to NULL.\n2. In the second iteration, for the next matched ARP entry sharing the same\nVCC, lec_arp_clear_vccs() is called again. It obtains a NULL vpriv from\nvcc->user_back (via LEC_VCC_PRIV(vcc)) and then attempts to dereference it\nvia `vcc->pop = vpriv->old_pop`, leading to a null-ptr-deref crash.\n\nFix this by adding a null check for vpriv before dereferencing\nit. If vpriv is already NULL, it means the VCC has been cleared\nby a previous call, so we can safely skip the cleanup and just\nclear the entry's vcc/recv_vcc pointers.\n\nThe entire cleanup block (including vcc_release_async()) is placed inside\nthe vpriv guard because a NULL vpriv indicates the VCC has already been\nfully released by a prior iteration \u2014 repeating the teardown would\nredundantly set flags and trigger callbacks on an already-closing socket.\n\nThe Fixes tag points to the initial commit because the entry->vcc path has\nbeen vulnerable since the original code. The entry->recv_vcc path was later\nadded by commit 8d9f73c0ad2f (\"atm: fix a memory leak of vcc->user_back\")\nwith the same pattern, and both paths are fixed here.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.167",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-23286"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8aff65a82b6389ec674d46e5b3d3ae6f07db5e3e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/30c9744a989feb22cfbb84170eb0e038a7a2c1da"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e9665986eb127290ceb535bd5d04d7a84265d94f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/622062f24644b4536d3f437e0cf7a8c4bb421665"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2d9f57ea29a1f1772373b98a509b44d49fda609e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7ea92ab075d809ec8a96669a5ecf00f752057875"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5f1cfea7921f5c126a441d973690eeba52677b64"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/101bacb303e89dc2e0640ae6a5e0fb97c4eb45bb"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}