In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
nfsd: drop the stateid, not the stateowner, on seqid_op replay retry<\/p>\n
In nfs4_preprocess_seqid_op() the stateid is obtained from
\nnfsd4_lookup_stateid(), which holds a reference on the nfs4_stid
\n(sc_count) but takes no reference on the stateowner. openlockstateid()
\nmerely casts that stid and likewise takes no reference.<\/p>\n
When nfsd4_cstate_assign_replay() returns -EAGAIN (the replay owner is
\nbeing torn down, RP_UNHASHED) it has not taken a stateowner reference on
\nthat path. The error handling nevertheless called
\nnfs4_put_stateowner(stp->st_stateowner), dropping an so_count reference
\nthe function never acquired — risking a stateowner refcount underflow and
\nuse-after-free — while leaking the sc_count reference held on the stid.
\nThe leaked stid reference can also stall a concurrent
\nnfsd4_close_open_stateid() waiting for sc_count to drop.<\/p>\n
Drop the reference actually held — the stid — before retrying. The
\nstateowner stays alive through the reference held by the stid. This mirrors
\nthe open path in nfsd4_process_open1(), where the put balances a reference
\nthat path explicitly holds on the stateowner.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
nfsd: drop the stateid, not the stateowner, on seqid_op replay retry<\/p>\n
In nfs4_preprocess_seqid_op() the stateid is obtained from
\nnf<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21610","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21610","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=21610"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21610"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21610"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}