Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:  libceph: validate OSD extent maps before cursor advance  net/ceph/osd_client.c:osd_sparse_read() validates that the sparse-read data length matches the summed extent lengths, but it does not validate that each OSD-supplied extent is monotonic and lies inside the original request range. A malformed authenticated OSD reply can advertise a far-forward nonzero extent offset with a matching data length and make the client advance the message-data cursor beyond the request buffer. This reaches the BUG_ON(!*length) assertion in ceph_msg_data_next() from the client receive path.  Impact: A malicious or compromised authenticated Ceph OSD peer can crash a kernel Ceph client via a malformed sparse-read reply.  Reject sparse extent maps that overflow, move backwards, overlap, or extend outside the original sparse-read request before advancing the cursor.  [ idryomov: perform sparse_extent_map_valid() check a bit earlier,   in CEPH_SPARSE_READ_DATA_LEN instead of CEPH_SPARSE_READ_DATA_PRE   state ]
Data source: kernel.org (416baaa9-dc9f-4396-8d5f-8c081fb06d67)