In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
sunrpc: wait for in-flight TLS handshake callback when cancel loses race<\/p>\n
When wait_for_completion_interruptible_timeout() in
\nsvc_tcp_handshake() returns 0 (timeout) or -ERESTARTSYS (signal) and
\ntls_handshake_cancel() then returns false, handshake_complete() has
\nwon the cancellation race: it has set HANDSHAKE_F_REQ_COMPLETED and
\nis about to invoke svc_tcp_handshake_done(), but the callback’s
\nside effects on xpt_flags and on svsk->sk_handshake_done have not
\nyet committed.<\/p>\n
The current code reads xpt_flags immediately to decide whether the
\nsession succeeded. Two races result.<\/p>\n
If the callback has executed set_bit(XPT_TLS_SESSION) but not yet
\nclear_bit(XPT_HANDSHAKE), svc_tcp_handshake() sees a session,
\nenqueues the transport, and returns. svc_xprt_received() then
\nclears XPT_BUSY, a worker thread picks the transport up, the
\ndispatcher in svc_handle_xprt() observes XPT_HANDSHAKE still set,
\nand xpo_handshake is invoked a second time. That svc_tcp_handshake()
\ncalls init_completion(&svsk->sk_handshake_done) while the original
\ncallback concurrently calls complete_all() on it, corrupting the
\nembedded swait_queue.<\/p>\n
If the callback has set HANDSHAKE_F_REQ_COMPLETED but not yet
\nentered svc_tcp_handshake_done(), svc_tcp_handshake() reads
\nXPT_TLS_SESSION as clear and tears the connection down even though
\nthe handshake is about to succeed.<\/p>\n
Wait for the callback to commit before inspecting xpt_flags. The
\ncompletion is guaranteed to fire because handshake_complete()
\ninvokes svc_tcp_handshake_done() unconditionally once it has set
\nHANDSHAKE_F_REQ_COMPLETED.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
sunrpc: wait for in-flight TLS handshake callback when cancel loses race<\/p>\n
When wait_for_completion_interruptible_timeout() in
\nsvc_t<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-6845","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/6845","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=6845"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6845"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6845"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}