{"id":"CVE-2023-53517","summary":"tipc: do not update mtu if msg_max is too small in mtu negotiation","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: do not update mtu if msg_max is too small in mtu negotiation\n\nWhen doing link mtu negotiation, a malicious peer may send Activate msg\nwith a very small mtu, e.g. 4 in Shuang's testing, without checking for\nthe minimum mtu, l-\u003emtu will be set to 4 in tipc_link_proto_rcv(), then\nn-\u003elinks[bearer_id].mtu is set to 4294967228, which is a overflow of\n'4 - INT_H_SIZE - EMSG_OVERHEAD' in tipc_link_mss().\n\nWith tipc_link.mtu = 4, tipc_link_xmit() kept printing the warning:\n\n tipc: Too large msg, purging xmit list 1 5 0 40 4!\n tipc: Too large msg, purging xmit list 1 15 0 60 4!\n\nAnd with tipc_link_entry.mtu 4294967228, a huge skb was allocated in\nnamed_distribute(), and when purging it in tipc_link_xmit(), a crash\nwas even caused:\n\n  general protection fault, probably for non-canonical address 0x2100001011000dd: 0000 [#1] PREEMPT SMP PTI\n  CPU: 0 PID: 0 Comm: swapper/0 Kdump: loaded Not tainted 6.3.0.neta #19\n  RIP: 0010:kfree_skb_list_reason+0x7e/0x1f0\n  Call Trace:\n   \u003cIRQ\u003e\n   skb_release_data+0xf9/0x1d0\n   kfree_skb_reason+0x40/0x100\n   tipc_link_xmit+0x57a/0x740 [tipc]\n   tipc_node_xmit+0x16c/0x5c0 [tipc]\n   tipc_named_node_up+0x27f/0x2c0 [tipc]\n   tipc_node_write_unlock+0x149/0x170 [tipc]\n   tipc_rcv+0x608/0x740 [tipc]\n   tipc_udp_recv+0xdc/0x1f0 [tipc]\n   udp_queue_rcv_one_skb+0x33e/0x620\n   udp_unicast_rcv_skb.isra.72+0x75/0x90\n   __udp4_lib_rcv+0x56d/0xc20\n   ip_protocol_deliver_rcu+0x100/0x2d0\n\nThis patch fixes it by checking the new mtu against tipc_bearer_min_mtu(),\nand not updating mtu if it is too small.","modified":"2026-04-11T12:46:48.403957Z","published":"2025-10-01T11:46:04.673Z","related":["SUSE-SU-2025:4189-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53517.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1dd7ae5e0cf5a56e513f7ab7ab9570b7496281d2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/259683001d7e879fea4b42084fb6560dd9408a7e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2bd4ff4ffb92113f8acd04dbaed83269172c24b4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/56077b56cd3fb78e1c8619e29581ba25a5c55e86"},{"type":"WEB","url":"https://git.kernel.org/stable/c/575e84d90a74c0b091b3417ba763ebb237aa0a8c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53517.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53517"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ed193ece2649c194a87a9d8470195760d367c075"},{"fixed":"2bd4ff4ffb92113f8acd04dbaed83269172c24b4"},{"fixed":"575e84d90a74c0b091b3417ba763ebb237aa0a8c"},{"fixed":"259683001d7e879fea4b42084fb6560dd9408a7e"},{"fixed":"1dd7ae5e0cf5a56e513f7ab7ab9570b7496281d2"},{"fixed":"56077b56cd3fb78e1c8619e29581ba25a5c55e86"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-53517.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.1.0"},{"fixed":"5.10.181"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.113"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.30"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.3.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-53517.json"}}],"schema_version":"1.7.5"}