{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2023-53585 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2023-53585 is a medium-severity use after free vulnerability in Linux kernel, published on 4 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2023-53585 and fix it if it is affected.\n\nWhat it is: CVE-2023-53585 is a medium-severity use after free vulnerability in Linux kernel, published on 4 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2023-53585 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2023-53585/ (Markdown: https://insights.sbomify.com/CVE-2023-53585/index.md)","id":"CVE-2023-53585","markdown":"https://insights.sbomify.com/CVE-2023-53585/index.md","name":"CVE-2023-53585","record":{"aliases":["BELL-CVE-2023-53585","DEBIAN-CVE-2023-53585","GHSA-39wr-crm4-gxmv","UBUNTU-CVE-2023-53585"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel BPF","requires_auth":"low_privilege","summary":"A use-after-free vulnerability in the Linux kernel's BPF subsystem allows attackers to cause a denial of service via unhashed UDP sockets.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: reject unhashed sockets in bpf_sk_assign\n\nThe semantics for bpf_sk_assign are as follows:\n\n    sk = some_lookup_func()\n    bpf_sk_assign(skb, sk)\n    bpf_sk_release(sk)\n\nThat is, the sk is not consumed by bpf_sk_assign. The function\ntherefore needs to make sure that sk lives long enough to be\nconsumed from __inet_lookup_skb. The path through the stack for a\nTCPv4 packet is roughly:\n\n  netif_receive_skb_core: takes RCU read lock\n    __netif_receive_skb_core:\n      sch_handle_ingress:\n        tcf_classify:\n          bpf_sk_assign()\n      deliver_ptype_list_skb:\n        deliver_skb:\n          ip_packet_type-\u003efunc == ip_rcv:\n            ip_rcv_core:\n            ip_rcv_finish_core:\n              dst_input:\n                ip_local_deliver:\n                  ip_local_deliver_finish:\n                    ip_protocol_deliver_rcu:\n                      tcp_v4_rcv:\n                        __inet_lookup_skb:\n                          skb_steal_sock\n\nThe existing helper takes advantage of the fact that everything\nhappens in the same RCU critical section: for sockets with\nSOCK_RCU_FREE set bpf_sk_assign never takes a reference.\nskb_steal_sock then checks SOCK_RCU_FREE again and does sock_put\nif necessary.\n\nThis approach assumes that SOCK_RCU_FREE is never set on a sk\nbetween bpf_sk_assign and skb_steal_sock, but this invariant is\nviolated by unhashed UDP sockets. A new UDP socket is created\nin TCP_CLOSE state but without SOCK_RCU_FREE set. That flag is only\nadded in udp_lib_get_port() which happens when a socket is bound.\n\nWhen bpf_sk_assign was added it wasn't possible to access unhashed\nUDP sockets from BPF, so this wasn't a problem. This changed\nin commit 0c48eefae712 (\"sock_map: Lift socket state restriction\nfor datagram sockets\"), but the helper wasn't adjusted accordingly.\nThe following sequence of events will therefore lead to a refcount\nleak:\n\n1. Add socket(AF_INET, SOCK_DGRAM) to a sockmap.\n2. Pull socket out of sockmap and bpf_sk_assign it. Since\n   SOCK_RCU_FREE is not set we increment the refcount.\n3. bind() or connect() the socket, setting SOCK_RCU_FREE.\n4. skb_steal_sock will now set refcounted = false due to\n   SOCK_RCU_FREE.\n5. tcp_v4_rcv() skips sock_put().\n\nFix the problem by rejecting unhashed sockets in bpf_sk_assign().\nThis matches the behaviour of __inet_lookup_skb which is ultimately\nthe goal of bpf_sk_assign().","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"bpf: reject unhashed sockets in bpf_sk_assign","id":"CVE-2023-53585","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2023"},"n_packages":0,"n_references":6,"next":{"headline":"scsi: target: Fix multiple LUN_RESET handling","id":"CVE-2023-53586"},"packages":[],"prev":{"headline":"ubifs: ubifs_releasepage: Remove ubifs_assert(0) to valid this process","id":"CVE-2023-53584"},"products":["Linux"],"published":"2025-10-04","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the Linux kernel's BPF subsystem allows attackers to cause a denial of service via unhashed UDP sockets.","url":"https://insights.sbomify.com/CVE-2023-53585/"}