{"id":21333,"date":"2026-09-12T04:31:03","date_gmt":"2026-09-11T20:31:03","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-81000"},"modified":"2026-09-12T04:31:03","modified_gmt":"2026-09-11T20:31:03","slug":"cve-2026-81000","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-81000","title":{"rendered":"CVE-2026-81000 &#8211; In the Linux kernel, the following vulnerability has been resolved:\n\nnet: tun: bound recei"},"content":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>net: tun: bound receive headroom<\/p>\n<p>tun_get_user() uses tun-&gt;align both as skb headroom and when choosing how<br \/>\nmuch packet data to keep linear. OVS can propagate an oversized headroom<br \/>\nrequest from another port to TUN or TAP.<\/p>\n<p>When align is larger than the usable space in a one-page skb head,<br \/>\nSKB_MAX_HEAD(align) underflows and the result becomes negative when stored<br \/>\nin good_linear. That value later wraps when assigned to the size_t linear<br \/>\nvariable, and tun_alloc_skb() can place skb-&gt;data outside the allocated<br \/>\nhead.<\/p>\n<p>Bound the headroom stored by TUN to the one-page skb-head budget and the<br \/>\nlargest non-sentinel 16-bit skb header offset. Leave one linear byte for<br \/>\nraw TUN and a complete Ethernet header for TAP, including NET_IP_ALIGN.<\/p>\n<p>Also pull the raw-TUN protocol byte and the TAP Ethernet header before<br \/>\naccessing them, so these checks remain safe for nonlinear skbs supplied by<br \/>\nother allocation paths.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>net: tun: bound receive headroom<\/p>\n<p>tun_get_user() uses tun-&gt;align both as skb headroom and when choosing how<br \/>\nmuch packet data to kee<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21333","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21333","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=21333"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21333"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21333"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}