CVE-2026-93267

/// Technical description

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

RDMA/core: Fix potential use after free in uverbs_free_dmah()

When accessing a dmah via the netlink path the only synchronization

mechanism for the said dmah is rdma_restrack_get().

Currently, rdma_restrack_del() is invoked at the end of

uverbs_free_dmah(), which is too late, since by that point

vendor-specific resources associated with the dmah might already be

freed. This can leave a short window where the dmah remains accessible

through restrack, leading to a potential use-after-free.

Fix this by moving the rdma_restrack_begin_del() call to the start of

uverbs_free_dmah(), ensuring that the dmah is removed from restrack

before its internal resources are released. This guarantees that no new

users hold references to a dmah that is in the process of destruction.

In addition, this change preserves the intended inverted order

between create and destroy routines: resources are added to

restrack at the end of successf

/// 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