In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
IB\/isert: post the full-feature receive buffers after session registration<\/p>\n
isert_put_login_tx() posts the full-feature receive buffers before
\n__transport_register_session() runs, so an initiator that does not wait
\nfor the final Login Response can still have a SCSI command executed
\nagainst an se_session whose se_tpg is NULL – the same oops as the
\nprevious patch, at target_submit+0xbe.<\/p>\n
Post them from isert_get_rx_pdu(), which the previous patch already uses
\nto send that response, and post them before that send: the receive queue
\nis filled at the moment the initiator is told it may use it. Allocating
\nthere keeps the existing property that a memory allocation failure cannot
\nhappen once the final Login Response is on the wire.<\/p>\n
The receive queue is already empty between the final Login Request and
\nisert_post_recvm(); this moves the second point later, from a median of
\n92 us to 172 us over 1200 logins. Only an initiator that sends before it
\nhas been told to can reach that window, and on IB and RoCE its send is
\nretried there until the buffers appear – isert_rdma_accept() asks for
\nrnr_retry_count = 7. iWARP has no RNR flow control, so there the same
\nsend terminates the connection instead.<\/p>\n
Measured over rxe, 400 login cycles per run, with an initiator that does
\nnot wait: an instrumented build counted no entries to isert_recv_done()
\nbefore the buffers are posted in 10 runs, where that initiator oopsed
\n8 of 10 unpatched runs and 5 of 10 with only the previous patch.<\/p>\n
Not tested: iWARP, discovery sessions over iSER, and real HCAs.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
IB\/isert: post the full-feature receive buffers after session registration<\/p>\n
isert_put_login_tx() posts the full-feature receive buf<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-25702","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/25702","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=25702"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25702"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25702"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}