{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-72373",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-72373"
  ],
  "published": "2026-08-15T06:04:33Z",
  "summary": "afs: Fix missing NULL pointer check in afs_break_some_callbacks()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nafs: Fix missing NULL pointer check in afs_break_some_callbacks()\n\nFix afs_break_some_callbacks() to check to see if afs_lookup_volume_rcu()\nreturned NULL (e.g. the specified volume is unknown).",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
    }
  ],
  "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": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-72373"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a99a617701186dc68c7b330d35fc2253f48e2ab2"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5492799ec5d27be3bd454dcaf046bc7054f637ae"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e3e59ff22a0de01ed0cf3a3e25558811abc3b70a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/794a01110390c1b76f59ece773fb0fbfd89c6f5c"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-17T05:50:24Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.5,
      "cvss_v3_severity": "High",
      "scenario": "AV:N - The bug is reached when an AFS fileserver sends a CB.CallBack/YFSCB.CallBack RPC over RxRPC to the kernel cache-manager listener; processing flows through SRXAFSCB_CallBack() to afs_break_some_callbacks() with no local syscall required.\nAC:L - A malicious or compromised fileserver that already has an encrypted RxRPC callback channel can reliably send a volume-level callback break (vnode=0, unique=0) for an arbitrary unknown volume ID, deterministically driving afs_lookup_volume_rcu() to return NULL and crash.\nPR:N - Exploitation requires no privileges on the victim host; a remote peer authenticated as a known AFS fileserver can deliver the crafted callback break without the attacker holding local user, capability, or namespace rights on the client.\nUI:N - Once AFS is mounted and a server callback connection exists, triggering the NULL dereference needs no further end-user action\u2014the fileserver can unilaterally send the malformed callback notification at any time.\nS:U - Impact is confined to kernel memory in the AFS client callback path (NULL dereference and possible oops/panic); it does not cross a VM, container, or IOMMU security boundary to affect a different authority.\nC:N - The failure mode is a NULL pointer dereference on volume->servers in afs_break_volume_callback(); there is no out-of-bounds access, use-after-free, or other memory corruption that could disclose kernel data.\nI:N - The bug causes an immediate invalid read through a NULL volume pointer and does not provide controlled writes, metadata corruption, or a path to arbitrary code execution beyond crashing the kernel.\nA:H - Hitting afs_break_volume_callback() with a NULL volume dereferences volume->servers under RCU, provoking a kernel oops or panic and denying availability to the entire system until reboot."
    }
  }
}