CVE-2026-80558

In the Linux kernel, the following vulnerability has been resolved:

libceph: Avoid using invalid osd indices from primary_temp

A corrupted osdmap received from a Ceph monitor or OSD may contain osd indices in its pgtemp, primarytemp, pgupmap, and pgupmapitems parts that don't exist, i.e., that are greater than maxosd or smaller than CEPHHOMELESSOSD (-1). These indices are used to create the up and acting set in cephpgtoupactingosds(), called from calctarget(). While most of these osd indices are checked, the one from primarytemp is not. Subsequently, this may lead to calctarget() returning this (potentially invalid) index as target osd for a (linger) request. Because the osdstate, osdweight, and osdaddr arrays only contain maxosd entries (with indices 0 to max_osd -1), this leads to out-of-bounds accesses when trying to read values from these arrays.

This patch fixes the issue by adding a check to gettemposds(), so that only valid osd indices from primarytemp are used, and it falls back to using the primary from pgtemp or the up set if it is invalid.

[ idryomov: changelog ]