{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2023-53246",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2023-53246"
  ],
  "published": "2025-09-15T14:48:04Z",
  "summary": "cifs: fix DFS traversal oops without CONFIG_CIFS_DFS_UPCALL",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: fix DFS traversal oops without CONFIG_CIFS_DFS_UPCALL\n\nWhen compiled with CONFIG_CIFS_DFS_UPCALL disabled, cifs_dfs_d_automount\nis NULL. cifs.ko logic for mapping CIFS_FATTR_DFS_REFERRAL attributes to\nS_AUTOMOUNT and corresponding dentry flags is retained regardless of\nCONFIG_CIFS_DFS_UPCALL, leading to a NULL pointer dereference in\nVFS follow_automount() when traversing a DFS referral link:\n  BUG: kernel NULL pointer dereference, address: 0000000000000000\n  ...\n  Call Trace:\n   <TASK>\n   __traverse_mounts+0xb5/0x220\n   ? cifs_revalidate_mapping+0x65/0xc0 [cifs]\n   step_into+0x195/0x610\n   ? lookup_fast+0xe2/0xf0\n   path_lookupat+0x64/0x140\n   filename_lookup+0xc2/0x140\n   ? __create_object+0x299/0x380\n   ? kmem_cache_alloc+0x119/0x220\n   ? user_path_at_empty+0x31/0x50\n   user_path_at_empty+0x31/0x50\n   __x64_sys_chdir+0x2a/0xd0\n   ? exit_to_user_mode_prepare+0xca/0x100\n   do_syscall_64+0x42/0x90\n   entry_SYSCALL_64_after_hwframe+0x72/0xdc\n\nThis fix adds an inline cifs_dfs_d_automount() {return -EREMOTE} handler\nwhen CONFIG_CIFS_DFS_UPCALL is disabled. An alternative would be to\navoid flagging S_AUTOMOUNT, etc. without CONFIG_CIFS_DFS_UPCALL. This\napproach was chosen as it provides more control over the error path.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.21-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v6",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v7",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v7l",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v8",
            "binary_version": "1:6.1.21-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.21-1+rpt1": {
            "linux_commit": "0afb5e98488aed7017b9bf321b575d0177feb7ed",
            "upstream_version": "6.1.21",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.23"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2023-53246"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/26a32a212bc540f4773cd6af8cf73e967d72569c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b64305185b76f1d5145ce594ff48f3f0e70695bd"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b7d854c33ab48e55fc233699bbefe39ec9bb5c05"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1e144b68208e98fd4602c842a7149ba5f41d87fb"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/179a88a8558bbf42991d361595281f3e45d7edfc"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}