In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
rds: drop incoming messages that cross network namespace boundaries<\/p>\n
rds_find_bound() looks up the destination socket using a global
\nrhashtable keyed solely on (addr, port, scope_id). Network namespaces
\nare not part of the key, so a sender in netns A can deliver an incoming
\nmessage (inc) to a socket that lives in a different netns B.<\/p>\n
When this happens, inc->i_conn points to an rds_connection whose c_net
\nis netns A, but the receiving rs lives in netns B. Once the child
\nprocess that created netns A exits, cleanup_net() calls
\nrds_loop_exit_net() -> rds_loop_kill_conns() -> rds_conn_destroy(),
\nfreeing that connection. If the survivor socket in netns B still holds
\nthe inc, any subsequent dereference of inc->i_conn is a use-after-free.<\/p>\n
There are two dangerous sites in rds_clear_recv_queue():
\n 1. inc->i_conn->c_lcong (offset 88 of freed rds_connection, size 200)
\n read via rds_recv_rcvbuf_delta() — confirmed by KASAN.
\n 2. inc->i_conn->c_trans->inc_free(inc) (function pointer at offset 80)
\n called via rds_inc_put() when the inc refcount reaches zero — same
\n race window, potential call-through-freed-object primitive.<\/p>\n
The bug is reachable from unprivileged user namespaces
\n(CLONE_NEWUSER + CLONE_NEWNET), available since Linux 3.8.<\/p>\n
Fix this by rejecting the delivery in rds_recv_incoming() when the
\nsocket returned by rds_find_bound() belongs to a different network
\nnamespace than the connection that carried the message. Use the
\nexisting rds_conn_net() \/ sock_net() helpers and net_eq() for the
\ncomparison.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
rds: drop incoming messages that cross network namespace boundaries<\/p>\n
rds_find_bound() looks up the destination socket using a globa<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-5429","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/5429","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=5429"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5429"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5429"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}