In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
RDMA\/ucma: Serialize join and leave on copy_to_user failure<\/p>\n
rdma_join_multicast() queues RoCE work that later reads the ucma_multicast
\nthrough event->param.ud.private_data, then list_add()s the CMA multicast
\nat the head of id_priv->mc_list. rdma_leave_multicast() matches only by
\nsockaddr and destroys the first hit.<\/p>\n
ucma_process_join() used to drop ctx->mutex after a successful join and
\nretake it only if copy_to_user() failed. Two concurrent JOIN_MCAST calls
\nwith the same address can therefore insert a second CMA entry before the
\nfirst thread’s leave. leave then cancels the newer work and the older
\nworker still dereferences the ucma_multicast that the first thread frees.<\/p>\n
Keep ctx->mutex held from rdma_join_multicast() through copy_to_user() and,
\non -EFAULT, through rdma_leave_multicast() so leave cannot miss this join.
\nDo not leave if join itself failed: that path never published this address
\non mc_list, and a leave-by-addr would destroy an earlier successful join.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
RDMA\/ucma: Serialize join and leave on copy_to_user failure<\/p>\n
rdma_join_multicast() queues RoCE work that later reads the ucma_multi<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-33322","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/33322","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=33322"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=33322"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=33322"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}