CVE-2026-89653 — ceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode
In the Linux kernel, the following vulnerability has been resolved: ceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode MDSMap export_targets entries are monito…
Published: 2026-09-11 · CVSS: 9.8 · CVSS 3.1
In the Linux kernel, the following vulnerability has been resolved: ceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode MDSMap export_targets entries are monitor controlled. check_new_map() uses each entry as a bit number in a fixed stack bitmap, so a rank outside the protocol namespace can make set_bit() write past the end of the array. Reject ranks outside CEPH_MAX_MDS while decoding the map. Do not validate against possible_max_rank here because maps may legitimately reference ranks beyond a temporarily reduced max_mds.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7