Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: ipv6: flowlabel: cap duplicate leases per socket ipv6_flowlabel_get() allocates an ipv6_fl_socklist entry for every successful GET. The recheck path for a compatible existing flowlabel links another lease without applying any lease admission check. Repeated GET requests for one shareable label can therefore grow a socket's lease list without bound. Reject a new unprivileged lease once the socket already holds FL_MAX_PER_SOCK leases. Check this on the shared recheck path so reuse of a globally interned label, including the fl_intern() collision path, is covered as well. New-label admission remains under the existing mem_check() policy. Use capable(CAP_NET_ADMIN) rather than ns_capable(), matching mem_check(). An unprivileged user must not bypass the cap by creating a user namespace and a netns where they have CAP_NET_ADMIN, which would still consume host memory. Check the capability only when the socket reaches the limit, so successful unprivileged GET requests below the cap do not generate a capability audit. Do the admission check before updating linger and expires so a rejected GET does not refresh the shared label, matching the existing socket-list allocation failure path.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 0159f716d8adbe85951cdf008d0afe27d874eaa6; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 6d917992c22b6029fc2dc1bd464b7f6709357161; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 2f1a6dd5c80ceb902f50449efe899f29cd7918e3; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 467467bf4209f9f8add0c648bae763f92a0224c3; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 8d6cd188508513503805c156165de38e4e4a8615 |
| Linux / Linux | affected 2.6.12; unaffected 0 before 2.6.12; unaffected 6.6.160 through 6.6.*; unaffected 6.12.112 through 6.12.*; unaffected 6.18.53 through 6.18.*; unaffected 7.2.7 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/0159f716d8adbe85951cdf008d0afe27d874eaa6
- https://git.kernel.org/stable/c/6d917992c22b6029fc2dc1bd464b7f6709357161
- https://git.kernel.org/stable/c/2f1a6dd5c80ceb902f50449efe899f29cd7918e3
- https://git.kernel.org/stable/c/467467bf4209f9f8add0c648bae763f92a0224c3
- https://git.kernel.org/stable/c/8d6cd188508513503805c156165de38e4e4a8615