CVE-2023-53525

/// Technical description

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

RDMA/cma: Allow UD qp_type to join multicast only

As for multicast:

- The SIDR is the only mode that makes sense;

- Besides PS_UDP, other port spaces like PS_IB is also allowed, as it is

UD compatible. In this case qkey also needs to be set [1].

This patch allows only UD qp_type to join multicast, and set qkey to

default if it's not set, to fix an uninit-value error: the ib->rec.qkey

field is accessed without being initialized.

=====================================================

BUG: KMSAN: uninit-value in cma_set_qkey drivers/infiniband/core/cma.c:510 [inline]

BUG: KMSAN: uninit-value in cma_make_mc_event+0xb73/0xe00 drivers/infiniband/core/cma.c:4570

cma_set_qkey drivers/infiniband/core/cma.c:510 [inline]

cma_make_mc_event+0xb73/0xe00 drivers/infiniband/core/cma.c:4570

cma_iboe_join_multicast drivers/infiniband/core/cma.c:4782 [inline]

rdma_join_multicast+0x2b83/0x30a0 drivers/infiniband/core/cma.c:4814

/// 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