{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2025-40255 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-40255 is a vulnerability in Linux, published on 4 Dec 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-2025-40255 and fix it if it is affected.\n\nWhat it is: CVE-2025-40255 is a vulnerability in Linux, published on 4 Dec 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-2025-40255 in the wild and no public exploit code.\n\nAffected product: Linux. 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-2025-40255/ (Markdown: https://insights.sbomify.com/CVE-2025-40255/index.md)","id":"CVE-2025-40255","markdown":"https://insights.sbomify.com/CVE-2025-40255/index.md","name":"CVE-2025-40255","record":{"aliases":["BELL-CVE-2025-40255","DEBIAN-CVE-2025-40255","GHSA-3mxh-p32w-7p56","UBUNTU-CVE-2025-40255"],"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 local attacker can crash the Linux kernel by triggering a null pointer dereference in the network timestamping ioctl handler.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()\n\nThe ethtool tsconfig Netlink path can trigger a null pointer\ndereference. A call chain such as:\n\n  tsconfig_prepare_data() -\u003e\n  dev_get_hwtstamp_phylib() -\u003e\n  vlan_hwtstamp_get() -\u003e\n  generic_hwtstamp_get_lower() -\u003e\n  generic_hwtstamp_ioctl_lower()\n\nresults in generic_hwtstamp_ioctl_lower() being called with\nkernel_cfg-\u003eifr as NULL.\n\nThe generic_hwtstamp_ioctl_lower() function does not expect\na NULL ifr and dereferences it, leading to a system crash.\n\nFix this by adding a NULL check for kernel_cfg-\u003eifr in\ngeneric_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL.","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: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()","id":"CVE-2025-40255","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"null_dereference","year":"2025"},"n_packages":0,"n_references":2,"next":{"headline":"xfrm: also call xfrm_state_delete_tunnel at destroy time for states that were never added","id":"CVE-2025-40256"},"packages":[],"prev":{"headline":"net: openvswitch: remove never-working support for setting nsh fields","id":"CVE-2025-40254"},"products":["Linux"],"published":"2025-12-04","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A local attacker can crash the Linux kernel by triggering a null pointer dereference in the network timestamping ioctl handler.","url":"https://insights.sbomify.com/CVE-2025-40255/"}