CVE-2024-35902

/// Technical description

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

net/rds: fix possible cp null dereference

cp might be null, calling cp->cp_conn would produce null dereference

[Simon Horman adds:]

Analysis:

* cp is a parameter of __rds_rdma_map and is not reassigned.

* The following call-sites pass a NULL cp argument to __rds_rdma_map()

- rds_get_mr()

- rds_get_mr_for_dest

* Prior to the code above, the following assumes that cp may be NULL

(which is indicative, but could itself be unnecessary)

trans_private = rs->rs_transport->get_mr(

sg, nents, rs, &mr->r_key, cp ? cp->cp_conn : NULL,

args->vec.addr, args->vec.bytes,

need_odp ? ODP_ZEROBASED : ODP_NOT_NEEDED);

* The code modified by this patch is guarded by IS_ERR(trans_private),

where trans_private is assigned as per the previous point in this analysis.

The only implementation of get_mr that I could locate is rds_ib_get_mr()

which can return an ERR_PTR if the conn (4th) argument is NULL.

* ret is se

/// 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