{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2024-26736",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2024-26736"
  ],
  "published": "2024-04-03T17:31:22Z",
  "summary": "afs: Increase buffer size in afs_update_volume_status()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nafs: Increase buffer size in afs_update_volume_status()\n\nThe max length of volume->vid value is 20 characters.\nSo increase idbuf[] size up to 24 to avoid overflow.\n\nFound by Linux Verification Center (linuxtesting.org) with SVACE.\n\n[DH: Actually, it's 20 + NUL, so increase it to 24 and use snprintf()]",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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": "6.1.80",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2024-26736"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5c27d85a69fa16a08813ba37ddfb4bbc9a1ed6b5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d9b5e2b7a8196850383c70d099bfd39e81ab6637"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e56662160fc24d28cb75ac095cc6415ae1bda43e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e8530b170e464017203e3b8c6c49af6e916aece1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6e6065dd25b661420fac19c34282b6c626fcd35e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d34a5e57632bb5ff825196ddd9a48ca403626dfa"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6ea38e2aeb72349cad50e38899b0ba6fbcb2af3d"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T11:52:36Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 8.1,
      "cvss_v3_severity": "High",
      "scenario": "AV:N - The value formatted into the undersized stack buffer originates entirely from a remote Volume Location server's `VL.GetEntryByNameU` reply (`ntohl(uvldb->volumeId[i])`, fs/afs/vlclient.c:77), and the call into `afs_update_volume_status()` is itself forced on demand by a remote fileserver returning VNOVOL/VMOVED abort codes (fs/afs/rotate.c:247,387). AFS VL traffic is unauthenticated rxrpc over UDP, so a rogue cell server or an on-path response spoofer reaches this code across the network.\nAC:H - Overflowing `idbuf[16]` requires `volume->vid` to exceed 10 decimal digits, but the on-wire `volumeId[]` field is `__be32` (fs/afs/afs_vl.h:123) and is the sole source of `volume->vid`, capping it at `4294967295`. The wire-format width is a hard constraint entirely beyond the attacker's control, so no attainable input triggers the write.\nPR:N - The attacker is the VL server (or a network entity spoofing its unauthenticated replies) and holds no account, credential, or capability on the target host. No local privilege on the victim is consumed anywhere along the `afs_select_fileserver` \u2192 `afs_check_volume_status` \u2192 `afs_update_volume_status` path.\nUI:N - On a configured AFS client `/afs` is already mounted at boot, and the volume-status refresh fires from routine background revalidation and from server-supplied VMOVED/VNOVOL responses without any victim action. The attacker drives the update himself via the fileserver's abort codes.\nS:U - Any corruption is confined to the AFS client's own kernel stack frame within the same kernel security authority. No VM, hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - A stack write past `idbuf` overwrites the adjacent locals in the same frame \u2014 the `new`/`old`/`discard`/`vldb` pointers and `idsz` \u2014 and corrupting `vldb` or `idsz` redirects the subsequent `memcmp`/`memcpy` of the volume name and the `afs_alloc_server_list()` walk, yielding an attacker-influenced kernel read. Per kernel guidance, memory corruption leverageable for disclosure is scored High.\nI:H - This is an out-of-bounds stack write, which per kernel guidance is High: the clobbered pointers are dereferenced and written through immediately afterwards (`memcpy(volume->name, vldb->name, AFS_MAXVOLNAME)`, `rcu_assign_pointer(volume->servers, new)`), giving a path to controlled kernel memory modification and control-flow influence.\nA:H - On any stack-protector kernel the 5-byte overrun smashes the canary and `__stack_chk_fail()` panics the machine; without it, the corrupted `vldb`/`new`/`old` pointers are dereferenced and freed (`kfree(vldb)`, `afs_put_serverlist()`), producing an oops. Either outcome is a full kernel crash."
    }
  }
}