In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
nfsd: release layout stid on setlease failure<\/p>\n
nfs4_alloc_stid() publishes the new stid into cl->cl_stateids via
\nidr_alloc_cyclic() under cl_lock before returning to
\nnfsd4_alloc_layout_stateid(). When nfsd4_layout_setlease() then
\nfails, the error path frees the layout stateid directly with
\nkmem_cache_free() without ever calling idr_remove(), leaving the
\nIDR slot pointing at freed slab memory. Any subsequent IDR walker
\n(states_show, client teardown) dereferences the dangling pointer.<\/p>\n
The correct teardown for an IDR-published stid is nfs4_put_stid(),
\nwhich removes the IDR slot under cl_lock, dispatches sc_free
\n(nfsd4_free_layout_stateid) to release ls->ls_file via
\nnfsd4_close_layout(), and drops the nfs4_file reference in its
\ntail.<\/p>\n
A second issue blocks that switch: nfsd4_free_layout_stateid()
\nunconditionally inspects ls->ls_fence_work via
\ndelayed_work_pending() under ls_lock, but
\nINIT_DELAYED_WORK(&ls->ls_fence_work, …) currently runs only
\nafter the setlease call. On the setlease-failure path the
\ndestructor would touch an uninitialized delayed_work.<\/p>\n
nfsd4_alloc_layout_stateid()
\n nfs4_alloc_stid() \/* idr_alloc_cyclic under cl_lock *\/
\n nfsd4_layout_setlease() \/* fails *\/
\n nfs4_put_stid()
\n nfsd4_free_layout_stateid()
\n delayed_work_pending(&ls->ls_fence_work) \/* needs INIT *\/
\n nfsd4_close_layout() \/* nfsd_file_put(ls->ls_file) *\/
\n put_nfs4_file()<\/p>\n
Fix by hoisting the ls_fenced \/ ls_fence_delay \/ INIT_DELAYED_WORK
\ninitialization above the nfsd4_layout_setlease() call, and replace
\nthe manual nfsd_file_put + put_nfs4_file + kmem_cache_free cleanup
\nwith a single nfs4_put_stid(stp).<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
nfsd: release layout stid on setlease failure<\/p>\n
nfs4_alloc_stid() publishes the new stid into cl->cl_stateids via
\nidr_alloc_cyclic()<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-14867","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/14867","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=14867"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14867"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14867"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}