linux — security advisory

{
  "id": "a3be986d3819307078801e035ca47a8b5c12bda8ca9d77c5f3c81565388d90f5",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2023-52523",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2023-52523",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Reject sk_msg egress redirects to non-TCP sockets With a SOCKMAP/SOCKHASH map and an sk_msg program user can steer messages sent from one TCP socket (s1) to actually egress from another TCP socket (s2): tcp_bpf_sendmsg(s1) // = sk_prot->sendmsg tcp_bpf_send_verdict(s1) // __SK_REDIRECT case tcp_bpf_sendmsg_redir(s2) tcp_bpf_push_locked(s2) tcp_bpf_push(s2) tcp_rate_check_app_limited(s2) // expects tcp_sock tcp_sendmsg_locked(s2) // ditto There is a hard-coded assumption in the call-chain, that the egress socket (s2) is a TCP socket. However in commit 122e6c79efe1 (\"sock_map: Update sock type checks for UDP\") we have enabled redirects to non-TCP sockets. This was done for the sake of BPF sk_skb programs. There was no indention to support sk_msg send-to-egress use case. As a result, attempts to send-to-egress through a non-TCP socket lead to a crash due to invalid downcast from sock to tcp_sock: BUG: kernel NULL pointer dereference, address: 000000000000002f ... Call Trace: ? show_regs+0x60/0x70 ? __die+0x1f/0x70 ? page_fault_oops+0x80/0x160 ? do_user_addr_fault+0x2d7/0x800 ? rcu_is_watching+0x11/0x50 ? exc_page_fault+0x70/0x1c0 ? asm_exc_page_fault+0x27/0x30 ? tcp_tso_segs+0x14/0xa0 tcp_write_xmit+0x67/0xce0 __tcp_push_pending_frames+0x32/0xf0 tcp_push+0x107/0x140 tcp_sendmsg_locked+0x99f/0xbb0 tcp_bpf_push+0x19d/0x3a0 tcp_bpf_sendmsg_redir+0x55/0xd0 tcp_bpf_send_verdict+0x407/0x550 tcp_bpf_sendm",
    "evidence": "osv:DEBIAN-CVE-2023-52523",
    "products": [
      {
        "name": {
          "value": "linux",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.64-1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "6.1.27-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "6.1.37-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "6.1.38-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "6.1.38-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "6.1.38-2~bpo11+1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "6.1.38-3",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "6.1.38-4",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "6.1.38-4~bpo11+1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "6.1.52-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "6.1.55-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "6.1.55-1~bpo11+1",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "linux",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.5.8-1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "linux",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.5.8-1",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "DEBIAN-CVE-2023-52523",
      "aliases": [
        "DEBIAN-CVE-2023-52523"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "6.1.64-1"
                }
              ]
            }
          ],
          "package": {
            "name": "linux",
            "purl": "pkg:deb/debian/linux?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "versions": [
            "6.1.27-1",
            "6.1.37-1",
            "6.1.38-1",
            "6.1.38-2",
            "6.1.38-2~bpo11+1",
            "6.1.38-3",
            "6.1.38-4",
            "6.1.38-4~bpo11+1",
            "6.1.52-1",
            "6.1.55-1",
            "6.1.55-1~bpo11+1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52523.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "6.5.8-1"
                }
              ]
            }
          ],
          "package": {
            "name": "linux",
            "purl": "pkg:deb/debian/linux?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52523.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "6.5.8-1"
                }
              ]
            }
          ],
          "package": {
            "name": "linux",
            "purl": "pkg:deb/debian/linux?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52523.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-26T18:02:42.925929526Z",
      "provider": "osv",
      "upstream": [
        "CVE-2023-52523"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2023-52523"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2023-52523",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 456672,
  "published_at": "2024-03-02T22:15:48.213+00:00"
}