In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ipv6: sr: restore network header before routing and forwarding<\/p>\n
ipv6_srh_rcv() runs with skb->data at the Segment Routing Header (SRH)
\nwhile skb_network_header() points at the IPv6 header.<\/p>\n
When segments_left > 0, ipv6_srh_rcv() previously restored the skb->data
\nposition by pushing sizeof(struct ipv6hdr), assuming the SRH immediately
\nfollowed the fixed IPv6 header. If another extension header (such as a
\nHop-by-Hop options header) precedes the SRH, skb_network_offset()
\nremained negative.<\/p>\n
This led to two problems:
\n1. During ip6_route_input(), fib6_rules_early_flow_dissect() invokes
\n __skb_flow_dissect() which passes the negative skb_network_offset()
\n to flow dissection, breaking BPF and C flow dissector logic.
\n2. If forwarded via ip6_forward() or redirected via act_mirred, downstream
\n handlers (like sch_fragment() or neighbour output) pass the negative
\n offset as an unsigned length, triggering OOB memcpy or buffer overflows.<\/p>\n
Fix this by pushing -skb_network_offset(skb) before routing, ensuring
\nskb_network_offset(skb) is 0 for route lookup \/ flow dissection as well as
\ndownstream forwarding. On the loopback path, pull skb_transport_offset(skb)
\nto restore skb->data to the SRH before looping back.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ipv6: sr: restore network header before routing and forwarding<\/p>\n
ipv6_srh_rcv() runs with skb->data at the Segment Routing Header (S<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-29251","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/29251","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=29251"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=29251"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=29251"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}