{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47162 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47162 is a critical use after free vulnerability in Linux kernel, published on 25 Mar 2024. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-47162 and fix it if it is affected.\n\nWhat it is: CVE-2021-47162 is a critical use after free vulnerability in Linux kernel, published on 25 Mar 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-47162 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-2021-47162/ (Markdown: https://insights.sbomify.com/CVE-2021-47162/index.md)","id":"CVE-2021-47162","markdown":"https://insights.sbomify.com/CVE-2021-47162/index.md","name":"CVE-2021-47162","record":{"aliases":["DEBIAN-CVE-2021-47162","GHSA-86fr-x2qv-cxp5","UBUNTU-CVE-2021-47162"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"none","summary":"A use-after-free vulnerability in the Linux kernel TIPC module allows attackers to cause crashes or potentially execute code via crafted network packets.","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":9.8,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: skb_linearize the head skb when reassembling msgs\n\nIt's not a good idea to append the frag skb to a skb's frag_list if\nthe frag_list already has skbs from elsewhere, such as this skb was\ncreated by pskb_copy() where the frag_list was cloned (all the skbs\nin it were skb_get'ed) and shared by multiple skbs.\n\nHowever, the new appended frag skb should have been only seen by the\ncurrent skb. Otherwise, it will cause use after free crashes as this\nappended frag skb are seen by multiple skbs but it only got skb_get\ncalled once.\n\nThe same thing happens with a skb updated by pskb_may_pull() with a\nskb_cloned skb. Li Shuang has reported quite a few crashes caused\nby this when doing testing over macvlan devices:\n\n  [] kernel BUG at net/core/skbuff.c:1970!\n  [] Call Trace:\n  []  skb_clone+0x4d/0xb0\n  []  macvlan_broadcast+0xd8/0x160 [macvlan]\n  []  macvlan_process_broadcast+0x148/0x150 [macvlan]\n  []  process_one_work+0x1a7/0x360\n  []  worker_thread+0x30/0x390\n\n  [] kernel BUG at mm/usercopy.c:102!\n  [] Call Trace:\n  []  __check_heap_object+0xd3/0x100\n  []  __check_object_size+0xff/0x16b\n  []  simple_copy_to_iter+0x1c/0x30\n  []  __skb_datagram_iter+0x7d/0x310\n  []  __skb_datagram_iter+0x2a5/0x310\n  []  skb_copy_datagram_iter+0x3b/0x90\n  []  tipc_recvmsg+0x14a/0x3a0 [tipc]\n  []  ____sys_recvmsg+0x91/0x150\n  []  ___sys_recvmsg+0x7b/0xc0\n\n  [] kernel BUG at mm/slub.c:305!\n  [] Call Trace:\n  []  \u003cIRQ\u003e\n  []  kmem_cache_free+0x3ff/0x400\n  []  __netif_receive_skb_core+0x12c/0xc40\n  []  ? kmem_cache_alloc+0x12e/0x270\n  []  netif_receive_skb_internal+0x3d/0xb0\n  []  ? get_rx_page_info+0x8e/0xa0 [be2net]\n  []  be_poll+0x6ef/0xd00 [be2net]\n  []  ? irq_exit+0x4f/0x100\n  []  net_rx_action+0x149/0x3b0\n\n  ...\n\nThis patch is to fix it by linearizing the head skb if it has frag_list\nset in tipc_buf_append(). Note that we choose to do this before calling\nskb_unshare(), as __skb_linearize() will avoid skb_copy(). Also, we can\nnot just drop the frag_list either as the early time.","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":"tipc: skb_linearize the head skb when reassembling msgs","id":"CVE-2021-47162","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2021"},"n_packages":0,"n_references":8,"next":{"headline":"tipc: wait and exit until all work queues are done","id":"CVE-2021-47163"},"packages":[],"prev":{"headline":"spi: spi-fsl-dspi: Fix a resource leak in an error handling path","id":"CVE-2021-47161"},"products":["Linux"],"published":"2024-03-25","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":"2026-08-05","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the Linux kernel TIPC module allows attackers to cause crashes or potentially execute code via crafted network packets.","url":"https://insights.sbomify.com/CVE-2021-47162/"}