In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ipv6: mcast: use copy-on-write RCU updates in ip6_mc_source()<\/p>\n
pmc->sflist is read locklessly under rcu_read_lock() by
\ninet6_mc_check() during packet reception in the UDP and RAW
\nmulticast receive paths.<\/p>\n
ip6_mc_source() mutated psl->sl_addr and psl->sl_count in-place
\nwhen adding or removing a source filter. Additionally, when expanding
\nthe filter buffer, newpsl was published via rcu_assign_pointer()
\nbefore writing the new source into the array.<\/p>\n
Because 16-byte struct in6_addr writes are not atomic and array
\nshifting is not synchronized with RCU readers, concurrent readers in
\ninet6_mc_check() could read torn IPv6 addresses or observe
\nduplicated\/missed source entries.<\/p>\n
Fix this by switching ip6_mc_source() to copy-on-write RCU updates:
\nallocate and fully populate newpsl before publishing it via
\nrcu_assign_pointer(), and reclaim the old filter via kfree_rcu(),
\nmatching ip6_mc_msfilter().<\/p>\n
Also remove the now unused IP6_SFBLOCK macro.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ipv6: mcast: use copy-on-write RCU updates in ip6_mc_source()<\/p>\n
pmc->sflist is read locklessly under rcu_read_lock() by
\ninet6_mc_che<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-29255","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/29255","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=29255"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=29255"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=29255"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}