{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21781 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21781 is a medium-severity vulnerability in Linux kernel, published on 27 Feb 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-2025-21781 and fix it if it is affected.\n\nWhat it is: CVE-2025-21781 is a medium-severity vulnerability in Linux kernel, published on 27 Feb 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-2025-21781 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-2025-21781/ (Markdown: https://insights.sbomify.com/CVE-2025-21781/index.md)","id":"CVE-2025-21781","markdown":"https://insights.sbomify.com/CVE-2025-21781/index.md","name":"CVE-2025-21781","record":{"aliases":["BELL-CVE-2025-21781","DEBIAN-CVE-2025-21781","GHSA-5v2w-fx47-6rq2","ROOT-OS-UBUNTU-2404-CVE-2025-21781","UBUNTU-CVE-2025-21781"],"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 null pointer dereference in the batman-adv kernel module during interface removal can cause a system crash, requiring a kernel patch.","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":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: fix panic during interface removal\n\nReference counting is used to ensure that\nbatadv_hardif_neigh_node and batadv_hard_iface\nare not freed before/during\nbatadv_v_elp_throughput_metric_update work is\nfinished.\n\nBut there isn't a guarantee that the hard if will\nremain associated with a soft interface up until\nthe work is finished.\n\nThis fixes a crash triggered by reboot that looks\nlike this:\n\nCall trace:\n batadv_v_mesh_free+0xd0/0x4dc [batman_adv]\n batadv_v_elp_throughput_metric_update+0x1c/0xa4\n process_one_work+0x178/0x398\n worker_thread+0x2e8/0x4d0\n kthread+0xd8/0xdc\n ret_from_fork+0x10/0x20\n\n(the batadv_v_mesh_free call is misleading,\nand does not actually happen)\n\nI was able to make the issue happen more reliably\nby changing hardif_neigh-\u003ebat_v.metric_work work\nto be delayed work. This allowed me to track down\nand confirm the fix.\n\n[sven@narfation.org: prevent entering batadv_v_elp_get_throughput without\n soft_iface]","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":"batman-adv: fix panic during interface removal","id":"CVE-2025-21781","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2025"},"n_packages":0,"n_references":8,"next":{"headline":"orangefs: fix a oob in orangefs_debug_write","id":"CVE-2025-21782"},"packages":[],"prev":{"headline":"drm/amdgpu: avoid buffer overflow attach in smu_sys_set_pp_table()","id":"CVE-2025-21780"},"products":["Linux"],"published":"2025-02-27","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 null pointer dereference in the batman-adv kernel module during interface removal can cause a system crash, requiring a kernel patch.","url":"https://insights.sbomify.com/CVE-2025-21781/"}