{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-46904 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-46904 is a medium-severity vulnerability in Linux kernel, published on 25 Feb 2024. 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-2021-46904 and fix it if it is affected.\n\nWhat it is: CVE-2021-46904 is a medium-severity vulnerability in Linux kernel, published on 25 Feb 2024. 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-2021-46904 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-2021-46904/ (Markdown: https://insights.sbomify.com/CVE-2021-46904/index.md)","id":"CVE-2021-46904","markdown":"https://insights.sbomify.com/CVE-2021-46904/index.md","name":"CVE-2021-46904","record":{"aliases":["DEBIAN-CVE-2021-46904","GHSA-r633-2867-crc8","UBUNTU-CVE-2021-46904"],"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 Linux kernel hso driver during tty unregistration can cause 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\nnet: hso: fix null-ptr-deref during tty device unregistration\n\nMultiple ttys try to claim the same the minor number causing a double\nunregistration of the same device. The first unregistration succeeds\nbut the next one results in a null-ptr-deref.\n\nThe get_free_serial_index() function returns an available minor number\nbut doesn't assign it immediately. The assignment is done by the caller\nlater. But before this assignment, calls to get_free_serial_index()\nwould return the same minor number.\n\nFix this by modifying get_free_serial_index to assign the minor number\nimmediately after one is found to be and rename it to obtain_minor()\nto better reflect what it does. Similary, rename set_serial_by_index()\nto release_minor() and modify it to free up the minor number of the\ngiven hso_serial. Every obtain_minor() should have corresponding\nrelease_minor() call.","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: hso: fix null-ptr-deref during tty device unregistration","id":"CVE-2021-46904","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2021"},"n_packages":0,"n_references":8,"next":{"headline":"net: hso: fix NULL-deref on disconnect regression","id":"CVE-2021-46905"},"packages":[],"prev":{"headline":"Missing authorization in n/a","id":"CVE-2021-46903"},"products":["Linux"],"published":"2024-02-25","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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A null pointer dereference in the Linux kernel hso driver during tty unregistration can cause a system crash.","url":"https://insights.sbomify.com/CVE-2021-46904/"}