{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-53034 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-53034 is a medium-severity vulnerability in Linux kernel, published on 24 Jun 2026. 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-2026-53034 and fix it if it is affected.\n\nWhat it is: CVE-2026-53034 is a medium-severity vulnerability in Linux kernel, published on 24 Jun 2026. 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-2026-53034 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-2026-53034/ (Markdown: https://insights.sbomify.com/CVE-2026-53034/index.md)","id":"CVE-2026-53034","markdown":"https://insights.sbomify.com/CVE-2026-53034/index.md","name":"CVE-2026-53034","record":{"aliases":["BELL-CVE-2026-53034","DEBIAN-CVE-2026-53034","GHSA-pwx6-fvf4-6686","ROOT-OS-DEBIAN-12-CVE-2026-53034","ROOT-OS-UBUNTU-2204-CVE-2026-53034","ROOT-OS-UBUNTU-2404-CVE-2026-53034","UBUNTU-CVE-2026-53034"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A race condition in the Linux kernel's BPF sockmap implementation allows a local attacker to trigger a null pointer dereference, causing a system crash.","user_interaction":"not_required","vuln_class":"null_dereference"},"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":[{"id":"CWE-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Fix af_unix null-ptr-deref in proto update\n\nunix_stream_connect() sets sk_state (`WRITE_ONCE(sk-\u003esk_state,\nTCP_ESTABLISHED)`) _before_ it assigns a peer (`unix_peer(sk) = newsk`).\nsk_state == TCP_ESTABLISHED makes sock_map_sk_state_allowed() believe that\nsocket is properly set up, which would include having a defined peer. IOW,\nthere's a window when unix_stream_bpf_update_proto() can be called on\nsocket which still has unix_peer(sk) == NULL.\n\n         CPU0 bpf                            CPU1 connect\n         --------                            ------------\n\n                                WRITE_ONCE(sk-\u003esk_state, TCP_ESTABLISHED)\nsock_map_sk_state_allowed(sk)\n...\nsk_pair = unix_peer(sk)\nsock_hold(sk_pair)\n                                sock_hold(newsk)\n                                smp_mb__after_atomic()\n                                unix_peer(sk) = newsk\n\nBUG: kernel NULL pointer dereference, address: 0000000000000080\nRIP: 0010:unix_stream_bpf_update_proto+0xa0/0x1b0\nCall Trace:\n  sock_map_link+0x564/0x8b0\n  sock_map_update_common+0x6e/0x340\n  sock_map_update_elem_sys+0x17d/0x240\n  __sys_bpf+0x26db/0x3250\n  __x64_sys_bpf+0x21/0x30\n  do_syscall_64+0x6b/0x3a0\n  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nInitial idea was to move peer assignment _before_ the sk_state update[1],\nbut that involved an additional memory barrier, and changing the hot path\nwas rejected.\nThen a NULL check during proto update in unix_stream_bpf_update_proto() was\nconsidered[2], but the follow-up discussion[3] focused on the root cause,\ni.e. sockmap update taking a wrong lock. Or, more specifically, missing\nunix_state_lock()[4].\nIn the end it was concluded that teaching sockmap about the af_unix locking\nwould be unnecessarily complex[5].\nComplexity aside, since BPF_PROG_TYPE_SCHED_CLS and BPF_PROG_TYPE_SCHED_ACT\nare allowed to update sockmaps, sock_map_update_elem() taking the unix\nlock, as it is currently implemented in unix_state_lock():\nspin_lock(\u0026unix_sk(s)-\u003elock), would be problematic. unix_state_lock() taken\nin a process context, followed by a softirq-context TC BPF program\nattempting to take the same spinlock -- deadlock[6].\nThis way we circled back to the peer check idea[2].\n\n[1]: https://lore.kernel.org/netdev/ba5c50aa-1df4-40c2-ab33-a72022c5a32e@rbox.co/\n[2]: https://lore.kernel.org/netdev/20240610174906.32921-1-kuniyu@amazon.com/\n[3]: https://lore.kernel.org/netdev/7603c0e6-cd5b-452b-b710-73b64bd9de26@linux.dev/\n[4]: https://lore.kernel.org/netdev/CAAVpQUA+8GL_j63CaKb8hbxoL21izD58yr1NvhOhU=j+35+3og@mail.gmail.com/\n[5]: https://lore.kernel.org/bpf/CAAVpQUAHijOMext28Gi10dSLuMzGYh+jK61Ujn+fZ-wvcODR2A@mail.gmail.com/\n[6]: https://lore.kernel.org/bpf/dd043c69-4d03-46fe-8325-8f97101435cf@linux.dev/\n\nSummary of scenarios where af_unix/stream connect() may race a sockmap\nupdate:\n\n1. connect() vs. bpf(BPF_MAP_UPDATE_ELEM), i.e. sock_map_update_elem_sys()\n\n   Implemented NULL check is sufficient. Once assigned, socket peer won't\n   be released until socket fd is released. And that's not an issue because\n   sock_map_update_elem_sys() bumps fd refcnf.\n\n2. connect() vs BPF program doing update\n\n   Update restricted per verifier.c:may_update_sockmap() to\n\n      BPF_PROG_TYPE_TRACING/BPF_TRACE_ITER\n      BPF_PROG_TYPE_SOCK_OPS (bpf_sock_map_update() only)\n      BPF_PROG_TYPE_SOCKET_FILTER\n      BPF_PROG_TYPE_SCHED_CLS\n      BPF_PROG_TYPE_SCHED_ACT\n      BPF_PROG_TYPE_XDP\n      BPF_PROG_TYPE_SK_REUSEPORT\n      BPF_PROG_TYPE_FLOW_DISSECTOR\n      BPF_PROG_TYPE_SK_LOOKUP\n\n   Plus one more race to consider:\n\n            CPU0 bpf                            CPU1 connect\n            --------                            ------------\n\n                                   WRITE_ONCE(sk-\u003esk_state, TCP_ESTABLISHED)\n   sock_map_sk_state_allowed(sk)\n                                   sock_hold(newsk)\n                                   smp_mb__after_atomic()\n                \n---truncated---","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, sockmap: Fix af_unix null-ptr-deref in proto update","id":"CVE-2026-53034","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":6,"next":{"headline":"bpf, sockmap: Fix af_unix iter deadlock","id":"CVE-2026-53035"},"packages":[],"prev":{"headline":"bpf, sockmap: Take state lock for af_unix iter","id":"CVE-2026-53033"},"products":["Linux"],"published":"2026-06-24","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":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-06-24","vendors":["Linux"]},"summary":"A race condition in the Linux kernel's BPF sockmap implementation allows a local attacker to trigger a null pointer dereference, causing a system crash.","url":"https://insights.sbomify.com/CVE-2026-53034/"}