In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
seg6: reset IP6CB after IPv6 decapsulation<\/p>\n
decap_and_validate() pulls the outer SRv6 headers and makes the inner
\npacket the skb network header. The IPv6 control block still contains
\nvalues collected while parsing the outer packet, including nhoff and
\nextension-header flags.<\/p>\n
End.DX6 and End.DT6 route the inner IPv6 packet directly to the IPv6
\ninput path. An unprivileged user can reach End.DT6 from a user and net
\nnamespace by installing a local SID and injecting an outer packet with
\nHop-by-Hop and Destination Options headers followed by an SRH and a
\nminimal inner IPv6 packet.<\/p>\n
The outer extension headers leave a large nhoff in IP6CB. After
\ndecapsulation, ip6_protocol_deliver_rcu() uses that stale offset on the
\ninner packet and reads beyond the skb head. KASAN reports:<\/p>\n
BUG: KASAN: slab-out-of-bounds in ip6_protocol_deliver_rcu
\n ip6_protocol_deliver_rcu+0x1118\/0x1450
\n ip6_input_finish+0x11b\/0x240
\n seg6_local_input_core+0xed\/0x2e0
\n lwtunnel_input+0x1e9\/0x4e0
\n ipv6_rthdr_rcv+0x525f\/0x6c50
\n ip6_protocol_deliver_rcu+0xcb7\/0x1450<\/p>\n
Before clearing IP6CB for an inner IPv6 packet, save its incoming
\ninterface index and L3 slave state. Restore both after the clear and set
\nnhoff to the inner IPv6 base-header nexthdr field.<\/p>\n
Use IP6CB(skb)->iif rather than skb->skb_iif because VRF processing can
\nreplace skb_iif with the L3 master while IP6CB keeps the receiving
\ninterface. Preserve IP6SKB_L3SLAVE for the same reason.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
seg6: reset IP6CB after IPv6 decapsulation<\/p>\n
decap_and_validate() pulls the outer SRv6 headers and makes the inner
\npacket the skb ne<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21309","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21309","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=21309"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21309"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21309"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}