DEBIAN-CVE-2026-80561

In the Linux kernel, the following vulnerability has been resolved:  libceph: fix multiple unsafe decodes in decodelocker()  decodelocker() in clslockclient.c contains three unsafe decode operations that allow a malicious or compromised OSD to trigger slab-out-of-bounds reads:  1. cephdecodecopy() at the lockeridt name field has no preceding    bounds check. With p == end after cephstartdecoding() accepts    structlen=0, this reads sizeof(cephentityname) = 9 bytes past    the validated buffer boundary.  2. p += sizeof(struct cephtimespec) after the lockerinfot header    is an unchecked pointer advance. A malicious OSD can position p    past end, causing all subsequent safe checks to pass against a    bogus boundary.  3. len = cephdecode32(p) has no preceding bounds check, and the    immediately following p += len is uncapped. A malicious OSD can    send len=0xffffffff, advancing p gigabytes past end and escaping    the decode window entirely.  Fix all three by replacing bare operations with their safe variants:   cephdecodecopy   -> cephdecodecopysafe   p += sizeof(...)  -> cephdecodeskipn   cephdecode32(p)  -> cephdecode32safe   p += len          -> cephdecodeskipn  A new label is added to return -EINVAL on any bounds violation. -EINVAL is appropriate here: the data received from the OSD is structurally malformed, which is an invalid argument to the decode contract regardless of whether the caller or the wire is at fault.  Attacker model: a malicious or compromised OSD in a multi-tenant Ceph deployment can trigger this against any kernel client that issues the lock.getinfo class method (e.g. during RBD exclusive lock acquisition) without any further privileges beyond OSD session establishment.  [ idryomov: use cephdecodeskip_string() to skip description, trim   changelog ]