CVE-2026-68158

/// Technical description

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

libceph: Fix multiplication overflow in decode_new_up_state_weight()

If a message of type CEPH_MSG_OSD_MAP contains a (maliciously) corrupted

osdmap, out-of-bounds memory accesses may occur in

decode_new_up_state_weight(). This happens because the bounds check for

the new_state part is based on calculating its length depending on a len

value read from the incoming message. This calculation may overflow

leading to an incorrect bounds check. Subsequently, out-of-bounds reads

may occur when decoding this part.

This patch switches the multiplication to use check_mul_overflow() to

abort processing the osdmap if an overflow occurred. Therefore,

osdmaps/messages containing large values for len that result in a

multiplication overflow are treated as invalid.

[ idryomov: rename new_state_len -> new_state_item_size, formatting ]

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References