{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: clear 'kern' flag from fallback sockets\n\nThe mptcp ULP extension relies on sk->sk_sock_kern being set correctly:\nIt prevents setsockopt(fd, IPPROTO_TCP, TCP_ULP, \"mptcp\", 6); from\nworking for plain tcp sockets (any userspace-exposed socket).\n\nBut in case of fallback, accept() can return a plain tcp sk.\nIn such case, sk is still tagged as 'kernel' and setsockopt will work.\n\nThis will crash the kernel, The subflow extension has a NULL ctx->conn\nmptcp socket:\n\nBUG: KASAN: null-ptr-deref in subflow_data_ready+0x181/0x2b0\nCall Trace:\n tcp_data_ready+0xf8/0x370\n [..]"
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "net/mptcp/protocol.c"
               ],
               "versions": [
                  {
                     "version": "cf7da0d66cc1",
                     "lessThan": "451f1eded7f5",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "cf7da0d66cc1",
                     "lessThan": "c26ac0ea3a91",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "cf7da0d66cc1",
                     "lessThan": "d6692b3b97bd",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "net/mptcp/protocol.c"
               ],
               "versions": [
                  {
                     "version": "5.6",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "5.6",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.88",
                     "lessThanOrEqual": "5.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.11",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.16",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/451f1eded7f56e93aaf52eb547ba97742d9c0e97"
            },
            {
               "url": "https://git.kernel.org/stable/c/c26ac0ea3a91c210cf90452e625dc441adf3e549"
            },
            {
               "url": "https://git.kernel.org/stable/c/d6692b3b97bdc165d150f4c1505751a323a80717"
            }
         ],
         "title": "mptcp: clear 'kern' flag from fallback sockets",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2021-47593",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}