{"cve":{"cve_id":"CVE-2021-47162","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00738,"epss_percentile":0.51552,"epss_as_of":"2026-08-28","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  []  <IRQ>\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.","published_at":"2024-03-25T09:16:15.857000Z","last_modified_at":"2026-08-04T10:16:49.790000Z","cvss_v3_score":9.8,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_v3_severity":"CRITICAL","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"none","ssvc_automatable":false,"ssvc_technical_impact":"partial","cwes":["CWE-416"],"nvd_references":["https://git.kernel.org/stable/c/b2c8d28c34b3070407cb1741f9ba3f15d0284b8b","https://git.kernel.org/stable/c/5489f30bb78ff0dafb4229a69632afc2ba20765c","https://git.kernel.org/stable/c/436d650d374329a591c30339a91fa5078052ed1e","https://git.kernel.org/stable/c/4b1761898861117c97066aea6c58f68a7787f0bf","https://git.kernel.org/stable/c/64d17ec9f1ded042c4b188d15734f33486ed9966","https://git.kernel.org/stable/c/6da24cfc83ba4f97ea44fc7ae9999a006101755c","https://git.kernel.org/stable/c/ace300eecbccaa698e2b472843c74a5f33f7dce8","https://git.kernel.org/stable/c/b7df21cf1b79ab7026f545e7bf837bd5750ac026"],"vuln_status":"Modified","trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-08-05T01:36:36.112582Z"},"effective_severity":"CRITICAL","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"45c8b7b175ceb2d542e0fe15247377bf3bce29ec","version_start_inclusive":true,"version_end":"b2c8d28c34b3070407cb1741f9ba3f15d0284b8b","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:45c8b7b175ceb2d542e0fe15247377bf3bce29ec:b2c8d28c34b3070407cb1741f9ba3f15d0284b8b"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"45c8b7b175ceb2d542e0fe15247377bf3bce29ec","version_start_inclusive":true,"version_end":"5489f30bb78ff0dafb4229a69632afc2ba20765c","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:45c8b7b175ceb2d542e0fe15247377bf3bce29ec:5489f30bb78ff0dafb4229a69632afc2ba20765c"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"45c8b7b175ceb2d542e0fe15247377bf3bce29ec","version_start_inclusive":true,"version_end":"436d650d374329a591c30339a91fa5078052ed1e","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:45c8b7b175ceb2d542e0fe15247377bf3bce29ec:436d650d374329a591c30339a91fa5078052ed1e"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"45c8b7b175ceb2d542e0fe15247377bf3bce29ec","version_start_inclusive":true,"version_end":"4b1761898861117c97066aea6c58f68a7787f0bf","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:45c8b7b175ceb2d542e0fe15247377bf3bce29ec:4b1761898861117c97066aea6c58f68a7787f0bf"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"45c8b7b175ceb2d542e0fe15247377bf3bce29ec","version_start_inclusive":true,"version_end":"64d17ec9f1ded042c4b188d15734f33486ed9966","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:45c8b7b175ceb2d542e0fe15247377bf3bce29ec:64d17ec9f1ded042c4b188d15734f33486ed9966"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"45c8b7b175ceb2d542e0fe15247377bf3bce29ec","version_start_inclusive":true,"version_end":"6da24cfc83ba4f97ea44fc7ae9999a006101755c","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:45c8b7b175ceb2d542e0fe15247377bf3bce29ec:6da24cfc83ba4f97ea44fc7ae9999a006101755c"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"45c8b7b175ceb2d542e0fe15247377bf3bce29ec","version_start_inclusive":true,"version_end":"ace300eecbccaa698e2b472843c74a5f33f7dce8","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:45c8b7b175ceb2d542e0fe15247377bf3bce29ec:ace300eecbccaa698e2b472843c74a5f33f7dce8"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"45c8b7b175ceb2d542e0fe15247377bf3bce29ec","version_start_inclusive":true,"version_end":"b7df21cf1b79ab7026f545e7bf837bd5750ac026","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:45c8b7b175ceb2d542e0fe15247377bf3bce29ec:b7df21cf1b79ab7026f545e7bf837bd5750ac026"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"d45ed6c1ff20d3640a31f03816ca2d48fb7d6f22","version_start_inclusive":true,"version_end":"d45ed6c1ff20d3640a31f03816ca2d48fb7d6f22","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:d45ed6c1ff20d3640a31f03816ca2d48fb7d6f22:d45ed6c1ff20d3640a31f03816ca2d48fb7d6f22"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"c19282fd54a19e4651a4e67836cd842082546677","version_start_inclusive":true,"version_end":"c19282fd54a19e4651a4e67836cd842082546677","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:c19282fd54a19e4651a4e67836cd842082546677:c19282fd54a19e4651a4e67836cd842082546677"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"4.1.14","version_start_inclusive":true,"version_end":"4.2","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:4.1.14:4.2"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"4.2.7","version_start_inclusive":true,"version_end":"4.3","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:4.2.7:4.3"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"4.3","version_start_inclusive":true,"version_end":"4.3","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:4.3:4.3"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"0","version_start_inclusive":true,"version_end":"4.3","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:0:4.3"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"4.4.271","version_start_inclusive":true,"version_end":"4.4.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:4.4.271:4.4.*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"4.9.271","version_start_inclusive":true,"version_end":"4.9.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:4.9.271:4.9.*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"4.14.235","version_start_inclusive":true,"version_end":"4.14.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:4.14.235:4.14.*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"4.19.193","version_start_inclusive":true,"version_end":"4.19.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:4.19.193:4.19.*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"5.4.124","version_start_inclusive":true,"version_end":"5.4.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:5.4.124:5.4.*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"5.10.42","version_start_inclusive":true,"version_end":"5.10.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:5.10.42:5.10.*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"5.12.9","version_start_inclusive":true,"version_end":"5.12.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:5.12.9:5.12.*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux","product_name":"Linux","version_start":"5.13","version_start_inclusive":true,"version_end":"*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:5.13:*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux-kernel","product_name":"linux_kernel","version_start":"4.3","version_start_inclusive":true,"version_end":"4.4.271","version_end_inclusive":false,"cpe23_uri":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux-kernel","product_name":"linux_kernel","version_start":"5.13","version_start_inclusive":true,"version_end":"5.13","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux-kernel","product_name":"linux_kernel","version_start":"5.13","version_start_inclusive":true,"version_end":"5.13","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*"},{"vendor_slug":"linux","vendor_name":"linux","product_slug":"linux-kernel","product_name":"linux_kernel","version_start":"5.13","version_start_inclusive":true,"version_end":"5.13","version_end_inclusive":true,"cpe23_uri":"cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*"}],"exploit_refs":[],"news":[],"references":[{"url":"https://git.kernel.org/stable/c/b2c8d28c34b3070407cb1741f9ba3f15d0284b8b","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/5489f30bb78ff0dafb4229a69632afc2ba20765c","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/436d650d374329a591c30339a91fa5078052ed1e","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/4b1761898861117c97066aea6c58f68a7787f0bf","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/64d17ec9f1ded042c4b188d15734f33486ed9966","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/6da24cfc83ba4f97ea44fc7ae9999a006101755c","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/ace300eecbccaa698e2b472843c74a5f33f7dce8","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/b7df21cf1b79ab7026f545e7bf837bd5750ac026","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2024-03-25T09:16:15.857000Z","label":"CVE published","source":null},{"type":"ssvc_changed","at":"2026-06-24T00:31:49.653458Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-24T00:31:49.653458Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-24T00:31:49.653458Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-08-04T10:18:26.048314Z","label":"CVSS score revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-08-04T10:18:26.048314Z","label":"CVSS score revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-08-04T10:18:26.048314Z","label":"CVSS score revised","source":"vulnrichment"}]}