In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/sched: cls_api: fix teardown of an adopted proto on insert-race loss<\/p>\n
In tc_new_tfilter() the create branch sets tp_created = 1 before calling
\ntcf_chain_tp_insert_unique(). When the caller loses the race (another
\nrequest inserted a proto at the same chain\/prio first), insert_unique()
\ndestroys the caller’s own tp_new and returns the winner’s proto with an
\nextra reference. tp_created was never cleared, so the loser’s errout
\npath treated the winner’s live proto as its own and called
\ntcf_chain_tp_delete_empty() on it, silently unlinking an active
\nclassifier that the winning request already advertised via
\nRTM_NEWTFILTER.<\/p>\n
Track the outcome of the insert step in a single tri-state variable so
\neach errout path reacts correctly:<\/p>\n
– TP_NOT_CREATED: no proto created; pursue the old path.
\n– TP_CREATED: proto inserted successfully; same code path as before.
\n– TP_NOT_OWNED: New – lost the insert race; tp is another request’s proto
\n (chain ref already released by tp_new’s destroy)<\/p>\n
Both errout reactions are single expressions derived from the state.<\/p>\n
This fix is motivated by the Sashiko’s automated review of Patch
\n(net\/sched: cls_api: Always acquire rtnl_lock when destroying locked
\nclassifiers) [1][2]. The review identified the silent-unlink behaviour of
\nan adopted proto’s teardown when a request loses the
\ntcf_chain_tp_insert_unique() race.<\/p>\n
[1] https:\/\/sashiko.dev\/#\/patchset\/20260801125632.360365-1-jhs%40mojatatu.com
\n[2] https:\/\/netdev-ai.bots.linux.dev\/sashiko\/#\/patchset\/20260801125632.360365-1-jhs%40mojatatu.com<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/sched: cls_api: fix teardown of an adopted proto on insert-race loss<\/p>\n
In tc_new_tfilter() the create branch sets tp_created = 1<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-25657","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/25657","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=25657"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25657"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25657"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}