In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/smc: fix TOCTOU race between smc_listen_out() and listener close<\/p>\n
smc_listen_out() reads lsmc->sk.sk_state without the listener lock,
\nthen acquires lock_sock_nested() only after the check passes. This
\nopens a window where smc_close_active() can transition the listener
\nto SMC_CLOSED, call smc_close_cleanup_listen() to drain the accept
\nqueue, and release the lock, all between the lockless read and the
\ndelayed lock acquisition:<\/p>\n
smc_listen_work (smc_hs_wq) smc_close_active()
\n ——————————- ————————-
\n release_sock(child)
\n if (sk_state == SMC_LISTEN) TRUE
\n lock_sock(listener)
\n sk_state = SMC_CLOSED
\n smc_close_cleanup_listen()
\n release_sock(listener)
\n flush_work(tcp_listen_work)
\n lock_sock_nested(listener)
\n smc_accept_enqueue(listener, child) \/* child enqueued on dead listener *\/<\/p>\n
smc_close_active() flushes only tcp_listen_work. Work items already
\ndispatched onto smc_hs_wq for the CLC handshake continue running
\nunguarded. smc_accept_enqueue() takes a sock_hold() on the child that
\nis never released, so the child smc_sock, its clcsock, and the
\nreference all leak. A remote peer that opens TCP connections while the
\nserver calls close() can exhaust kernel memory.<\/p>\n
Move lock_sock_nested() to before the sk_state check so that the test
\nand the enqueue are atomic under the listener lock.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/smc: fix TOCTOU race between smc_listen_out() and listener close<\/p>\n
smc_listen_out() reads lsmc->sk.sk_state without the listener<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-11266","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/11266","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=11266"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11266"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11266"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}