In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
tipc: fix u16 MTU truncation in media and bearer MTU validation<\/p>\n
Both TIPC_NL_MEDIA_SET and TIPC_NL_BEARER_SET accept user-supplied
\nMTU values but only enforce a minimum bound, not a maximum. When a user
\nsets the MTU to a value exceeding U16_MAX (65535), it passes validation
\nbut is silently truncated when assigned to u16 fields l->mtu and
\nl->advertised_mtu in tipc_link_create(). Values like 65536 (0x10000)
\ntruncate to 0, causing a division by zero in tipc_link_set_queue_limits()
\nwhich computes TIPC_MAX_PUBL \/ (l->mtu \/ ITEM_SIZE). Other overflowing
\nvalues (e.g. 65537-131071) produce small incorrect MTU values, resulting
\nin link malfunction behaviors.<\/p>\n
Crash stack (triggered as unprivileged user via user namespace):<\/p>\n
tipc_link_set_queue_limits net\/tipc\/link.c:2531
\n tipc_link_create net\/tipc\/link.c:520
\n tipc_node_check_dest net\/tipc\/node.c:1279
\n tipc_disc_rcv net\/tipc\/discover.c:252
\n tipc_rcv net\/tipc\/node.c:2129
\n tipc_udp_recv net\/tipc\/udp_media.c:392<\/p>\n
Two independent paths lack the upper bound check:
\n1. tipc_udp_mtu_bad() — called from __tipc_nl_media_set() (MEDIA_SET)
\n2. inline check in __tipc_nl_bearer_set() at bearer.c:1160 (BEARER_SET)<\/p>\n
Fix both by rejecting MTU values above U16_MAX.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
tipc: fix u16 MTU truncation in media and bearer MTU validation<\/p>\n
Both TIPC_NL_MEDIA_SET and TIPC_NL_BEARER_SET accept user-supplied<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-5415","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/5415","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=5415"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5415"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5415"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}