CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's libceph component, where malformed CRUSH maps can lead to a situation where one bucket inadvertently reuses another bucket's workspace, potentially causing out-of-bounds writes. This flaw can result in memory corruption, which may compromise system stability or security. Administrators of systems running affected Linux kernel versions should prioritize applying the patch to mitigate the risk of exploitation.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: libceph: reject buckets with mismatched CRUSH ids crush_decode() stores bucket data by array slot, and the mapper later derives the per-bucket workspace index from the decoded bucket id. A malformed map can therefore make one bucket reuse another bucket's workspace by encoding an id different from -1 - slot. For uniform buckets, the second replica selection expands the source bucket's permutation into that aliased workspace buffer. If the source bucket is larger than the aliased bucket, the write runs past the smaller permutation array and can escape the kvmalloc'd CRUSH workspace. KASAN reports a slab OOB write of 4 bytes in bucket_perm_choose(). Reject buckets whose encoded id does not match their array slot. Valid CRUSH maps already use the canonical negative id corresponding to the bucket slot, so this restores the invariant expected by work->work[-1 - in->id] without changing valid map behavior.