Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: tipc: fix u16 MTU truncation in media and bearer MTU validation Both TIPC_NL_MEDIA_SET and TIPC_NL_BEARER_SET accept user-supplied MTU values but only enforce a minimum bound, not a maximum. When a user sets the MTU to a value exceeding U16_MAX (65535), it passes validation but is silently truncated when assigned to u16 fields l->mtu and l->advertised_mtu in tipc_link_create(). Values like 65536 (0x10000) truncate to 0, causing a division by zero in tipc_link_set_queue_limits() which computes TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE). Other overflowing values (e.g. 65537-131071) produce small incorrect MTU values, resulting in link malfunction behaviors. Crash stack (triggered as unprivileged user via user namespace): tipc_link_set_queue_limits net/tipc/link.c:2531 tipc_link_create net/tipc/link.c:520 tipc_node_check_dest net/tipc/node.c:1279 tipc_disc_rcv net/tipc/discover.c:252 tipc_rcv net/tipc/node.c:2129 tipc_udp_recv net/tipc/udp_media.c:392 Two independent paths lack the upper bound check: 1. tipc_udp_mtu_bad() -- called from __tipc_nl_media_set() (MEDIA_SET) 2. inline check in __tipc_nl_bearer_set() at bearer.c:1160 (BEARER_SET) Fix both by rejecting MTU values above U16_MAX.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 901271e0403af638c224987c2a4e55cebade7e91 before 8bfdfe0dbb36a650b7c4dec1aeae078319938a0b; affected 901271e0403af638c224987c2a4e55cebade7e91 before dc4b577a083b361d25e118dc96d8281255ebe22c; affected 901271e0403af638c224987c2a4e55cebade7e91 before dfdfd987f1917c84766e097a6120a1f3f1634940; affected 901271e0403af638c224987c2a4e55cebade7e91 before f02334a9e378f7e07232b26dc3d2ab353339f040; affected 901271e0403af638c224987c2a4e55cebade7e91 before f4013598b69457dbea350df52e52daea6faef8eb; affected 901271e0403af638c224987c2a4e55cebade7e91 before 1b8fb5a20508bfb0db854e01214888c761b3a911; affected 901271e0403af638c224987c2a4e55cebade7e91 before c1cda72f6acec02ebd45d913bf8527ff77336ba6; affected 901271e0403af638c224987c2a4e55cebade7e91 before 9f29cd8a8e7901a2617c8064ce9f50fc67b97cb8 |
| Linux / Linux | affected 4.18; unaffected 0 before 4.18; unaffected 5.10.265 through 5.10.*; unaffected 5.15.216 through 5.15.*; unaffected 6.1.183 through 6.1.*; unaffected 6.6.148 through 6.6.*; unaffected 6.12.101 through 6.12.*; unaffected 6.18.42 through 6.18.*; unaffected 7.1.6 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/8bfdfe0dbb36a650b7c4dec1aeae078319938a0b
- https://git.kernel.org/stable/c/dc4b577a083b361d25e118dc96d8281255ebe22c
- https://git.kernel.org/stable/c/dfdfd987f1917c84766e097a6120a1f3f1634940
- https://git.kernel.org/stable/c/f02334a9e378f7e07232b26dc3d2ab353339f040
- https://git.kernel.org/stable/c/f4013598b69457dbea350df52e52daea6faef8eb
- https://git.kernel.org/stable/c/1b8fb5a20508bfb0db854e01214888c761b3a911
- https://git.kernel.org/stable/c/c1cda72f6acec02ebd45d913bf8527ff77336ba6
- https://git.kernel.org/stable/c/9f29cd8a8e7901a2617c8064ce9f50fc67b97cb8
ADP enrichment
No English description supplied.
No references supplied.