{"id":11924,"date":"2026-09-04T18:53:58","date_gmt":"2026-09-04T10:53:58","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-74743"},"modified":"2026-09-04T18:53:58","modified_gmt":"2026-09-04T10:53:58","slug":"cve-2026-74743","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-74743","title":{"rendered":"CVE-2026-74743 [CRITICAL] &#8211; In the Linux kernel, the following vulnerability has been resolved:\n\nmacvlan: inherit need"},"content":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>macvlan: inherit needed_headroom and needed_tailroom from lowerdev<\/p>\n<p>macvlan devices inherit hard_header_len from lowerdev during macvlan_init(),<br \/>\nbut leave needed_headroom and needed_tailroom set to 0.<\/p>\n<p>When the underlying lowerdev requires extra headroom or tailroom for<br \/>\nheaders\/trailers (e.g. macsec, ipsec, wireguard, tunnels, or veth with rx<br \/>\nheadroom), upper layers calculating packet headroom and tailroom fail to<br \/>\nreserve sufficient space.<\/p>\n<p>This can result in reallocation overhead, skb headroom underflows, or KASAN<br \/>\nslab-use-after-free crashes when dev_hard_header() \/ macvlan_hard_header()<br \/>\nprepends header data or when lower devices append tailroom.<\/p>\n<p>Fix this by:<br \/>\n1. Inheriting needed_headroom and needed_tailroom from lowerdev in macvlan_init().<br \/>\n2. Propagating needed_headroom and needed_tailroom updates to attached macvlans<br \/>\n   in macvlan_device_event() when receiving NETDEV_FEAT_CHANGE events.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>macvlan: inherit needed_headroom and needed_tailroom from lowerdev<\/p>\n<p>macvlan devices inherit hard_header_len from lowerdev during ma<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-11924","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/11924","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=11924"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11924"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11924"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}