{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21884 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21884 is a high-severity use after free vulnerability in Linux kernel, published on 27 Mar 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-2025-21884 and fix it if it is affected.\n\nWhat it is: CVE-2025-21884 is a high-severity use after free vulnerability in Linux kernel, published on 27 Mar 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-2025-21884 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-2025-21884/ (Markdown: https://insights.sbomify.com/CVE-2025-21884/index.md)","id":"CVE-2025-21884","markdown":"https://insights.sbomify.com/CVE-2025-21884/index.md","name":"CVE-2025-21884","record":{"aliases":["AZL-62830","BELL-CVE-2025-21884","DEBIAN-CVE-2025-21884","GHSA-f4wj-m43r-79jr","ROOT-OS-DEBIAN-13-CVE-2025-21884","ROOT-OS-UBUNTU-2404-CVE-2025-21884","UBUNTU-CVE-2025-21884"],"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 use-after-free vulnerability in Linux kernel network sockets can cause system crashes or warnings during namespace cleanup.","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":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: better track kernel sockets lifetime\n\nWhile kernel sockets are dismantled during pernet_operations-\u003eexit(),\ntheir freeing can be delayed by any tx packets still held in qdisc\nor device queues, due to skb_set_owner_w() prior calls.\n\nThis then trigger the following warning from ref_tracker_dir_exit() [1]\n\nTo fix this, make sure that kernel sockets own a reference on net-\u003epassive.\n\nAdd sk_net_refcnt_upgrade() helper, used whenever a kernel socket\nis converted to a refcounted one.\n\n[1]\n\n[  136.263918][   T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at\n[  136.263918][   T35]      sk_alloc+0x2b3/0x370\n[  136.263918][   T35]      inet6_create+0x6ce/0x10f0\n[  136.263918][   T35]      __sock_create+0x4c0/0xa30\n[  136.263918][   T35]      inet_ctl_sock_create+0xc2/0x250\n[  136.263918][   T35]      igmp6_net_init+0x39/0x390\n[  136.263918][   T35]      ops_init+0x31e/0x590\n[  136.263918][   T35]      setup_net+0x287/0x9e0\n[  136.263918][   T35]      copy_net_ns+0x33f/0x570\n[  136.263918][   T35]      create_new_namespaces+0x425/0x7b0\n[  136.263918][   T35]      unshare_nsproxy_namespaces+0x124/0x180\n[  136.263918][   T35]      ksys_unshare+0x57d/0xa70\n[  136.263918][   T35]      __x64_sys_unshare+0x38/0x40\n[  136.263918][   T35]      do_syscall_64+0xf3/0x230\n[  136.263918][   T35]      entry_SYSCALL_64_after_hwframe+0x77/0x7f\n[  136.263918][   T35]\n[  136.343488][   T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at\n[  136.343488][   T35]      sk_alloc+0x2b3/0x370\n[  136.343488][   T35]      inet6_create+0x6ce/0x10f0\n[  136.343488][   T35]      __sock_create+0x4c0/0xa30\n[  136.343488][   T35]      inet_ctl_sock_create+0xc2/0x250\n[  136.343488][   T35]      ndisc_net_init+0xa7/0x2b0\n[  136.343488][   T35]      ops_init+0x31e/0x590\n[  136.343488][   T35]      setup_net+0x287/0x9e0\n[  136.343488][   T35]      copy_net_ns+0x33f/0x570\n[  136.343488][   T35]      create_new_namespaces+0x425/0x7b0\n[  136.343488][   T35]      unshare_nsproxy_namespaces+0x124/0x180\n[  136.343488][   T35]      ksys_unshare+0x57d/0xa70\n[  136.343488][   T35]      __x64_sys_unshare+0x38/0x40\n[  136.343488][   T35]      do_syscall_64+0xf3/0x230\n[  136.343488][   T35]      entry_SYSCALL_64_after_hwframe+0x77/0x7f","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":"net: better track kernel sockets lifetime","id":"CVE-2025-21884","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2025"},"n_packages":0,"n_references":4,"next":{"headline":"RDMA/bnxt_re: Fix the page details for the srq created by kernel consumers","id":"CVE-2025-21885"},"packages":[],"prev":{"headline":"ice: Fix deinitializing VF in error path","id":"CVE-2025-21883"},"products":["Linux"],"published":"2025-03-27","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":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"A use-after-free vulnerability in Linux kernel network sockets can cause system crashes or warnings during namespace cleanup.","url":"https://insights.sbomify.com/CVE-2025-21884/"}