{"id":17486,"date":"2026-09-05T02:31:10","date_gmt":"2026-09-04T18:31:10","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-80906"},"modified":"2026-09-05T02:31:10","modified_gmt":"2026-09-04T18:31:10","slug":"cve-2026-80906","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-80906","title":{"rendered":"CVE-2026-80906 &#8211; In the Linux kernel, the following vulnerability has been resolved:\n\nnet: packet: fix wron"},"content":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>net: packet: fix wrong transport_header when sending VLAN-tagged frame<\/p>\n<p>In packet_parse_headers(), when processing a VLAN-tagged frame,<br \/>\nskb_set_network_header() is called to advance network_header past the<br \/>\nVLAN tag to the inner protocol header. skb_probe_transport_header() is<br \/>\nthen called with skb-&gt;protocol still set to the outer VLAN EtherType<br \/>\n(e.g. ETH_P_8021Q), while nhoff (derived from skb_network_offset())<br \/>\nalready points past the VLAN tag to the inner protocol header.<\/p>\n<p>In __skb_flow_dissect(), proto is initialized to ETH_P_8021Q and nhoff<br \/>\npoints past the VLAN tag. When the dissector hits case ETH_P_8021Q, it<br \/>\nreads a struct vlan_hdr at nhoff via __skb_header_pointer(), but that<br \/>\noffset contains the inner protocol header (e.g. an IP header). The bytes<br \/>\nare misinterpreted as a VLAN header, yielding a garbage encapsulated<br \/>\nEtherType that matches no known protocol. The dissector returns false,<br \/>\nso skb_probe_transport_header() never calls skb_set_transport_header(),<br \/>\nleaving transport_header at its uninitialized sentinel value (~0U).<\/p>\n<p>Move skb_probe_transport_header() to before skb_set_network_header(). At<br \/>\nthe time skb_probe_transport_header() is called, network_header still<br \/>\npoints to the VLAN header, so nhoff correctly points to the VLAN header.<br \/>\nThe flow dissector can then parse the VLAN header, extract the inner<br \/>\nEtherType, and advance nhoff to the inner protocol header, allowing<br \/>\ntransport_header to be set correctly.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>net: packet: fix wrong transport_header when sending VLAN-tagged frame<\/p>\n<p>In packet_parse_headers(), when processing a VLAN-tagged fr<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-17486","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/17486","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=17486"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=17486"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=17486"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}