In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/packet: reset the MAC header on the packet-socket transmit path<\/p>\n
packet_parse_headers() resets the MAC header only for a SOCK_RAW frame
\nwhose socket did not bind a protocol. A protocol-bound SOCK_RAW socket,
\nany SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave
\nskb->mac_header unset here.<\/p>\n
For frames sent via __dev_queue_xmit() this is harmless: it resets the
\nMAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS
\npath uses dev_direct_xmit(), which does not, so the frame reaches
\nndo_start_xmit() with the MAC header unset. A driver that reads
\neth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an
\nout-of-bounds access ~64 KiB past the head — the same class fixed for
\none consumer in commit f5089008f90c (“macsec: do not read an unset MAC
\nheader in macsec_encrypt()”).<\/p>\n
packet_parse_headers() runs only on the transmit path, where skb->data
\npoints at the start of the L2 header for every packet-socket type
\nregardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied
\nheader and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC
\nheader unconditionally, mirroring __dev_queue_xmit(), so the frame is
\nanchored on the bypass path too.<\/p>\n
Found by 0sec (https:\/\/0sec.ai) using automated source analysis;
\nverified against source and matched to the macsec KASAN report in
\nf5089008f90c. Compile-tested.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/packet: reset the MAC header on the packet-socket transmit path<\/p>\n
packet_parse_headers() resets the MAC header only for a SOCK_R<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-11253","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/11253","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=11253"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11253"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11253"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}