In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
rds: filter RDS_INFO_* getsockopt by caller’s netns<\/p>\n
The RDS_INFO_* family of getsockopt(2) options reads several
\nfile-scope global lists that are not per-netns:<\/p>\n
rds_sock_info \/ rds6_sock_info,
\n rds_sock_inc_info \/ rds6_sock_inc_info -> rds_sock_list
\n rds_tcp_tc_info \/ rds6_tcp_tc_info -> rds_tcp_tc_list
\n rds_conn_info \/ rds6_conn_info,
\n rds_conn_message_info_cmn (for the *_SEND_MESSAGES and
\n *_RETRANS_MESSAGES variants),
\n rds_for_each_conn_info (for RDS_INFO_IB_CONNECTIONS)
\n -> rds_conn_hash[]<\/p>\n
The handlers do not filter by the caller’s network namespace.
\nrds_info_getsockopt() has no netns or capable() check, and
\nrds_create() has no capable() check, so AF_RDS is reachable from
\nan unprivileged user namespace. As a result, an unprivileged
\ncaller in a fresh user_ns plus netns can read the bound address
\nand sock inode of every RDS socket on the host, the peer address
\nof incoming messages on every RDS socket on the host, the peer
\naddress and TCP sequence numbers of every rds-tcp connection on
\nthe host, and the peer address and RDS sequence numbers of every
\nRDS connection on the host.<\/p>\n
The rds-tcp transport is reachable from a non-initial netns (see
\nrds_set_transport()), so a one-shot init_net gate at
\nrds_info_getsockopt() would deny legitimate per-netns visibility
\nto rds-tcp callers. Instead, filter at each handler by comparing
\nthe netns of the caller’s socket to the netns of the list entry,
\nor to rds_conn_net(conn) for connection paths. Only copy entries
\nwhose netns matches the caller. Counters (RDS_INFO_COUNTERS) are
\naggregate statistics and remain global.<\/p>\n
Reproducer (KASAN VM, rds and rds_tcp loaded): an AF_RDS socket
\nbinds 127.0.0.1:4242 in init_net as root. A child process enters
\na fresh user_ns plus netns and opens AF_RDS there, then calls
\ngetsockopt(SOL_RDS, RDS_INFO_SOCKETS). Before this change, the
\nchild sees the init_net socket. After this change, the child
\nsees zero entries.<\/p>\n
Drop the rds_sock_count, rds_tcp_tc_count, and rds6_tcp_tc_count
\nglobals. v2 used them for the size precheck and lens->nr; v3
\nreplaced the precheck with a per-ns count from a first pass over
\nthe list, so the globals have no remaining readers. The matching
\nincrements and decrements in rds_create()\/rds_destroy_sock() and
\nrds_tcp_set_callbacks()\/rds_tcp_restore_callbacks() go away with
\nthem. Reported by the kernel test robot under clang W=1.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
rds: filter RDS_INFO_* getsockopt by caller’s netns<\/p>\n
The RDS_INFO_* family of getsockopt(2) options reads several
\nfile-scope global<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-28708","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/28708","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=28708"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=28708"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=28708"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}