CVE-2024-35902: net/rds: fix possible cp null dereference

Vulnerability summary

CVE-2024-35902 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in debian debian_linux. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.9% of scored vulnerabilities.

Timeline

1. 19-05-2024
   PublishedVulnerability first disclosed.
2. 15-10-2026
   Last modifiedVulnerability information updated.

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 set to PTR_ERR(trans_private). rds_ib_get_mr can return ERR_PTR(-ENODEV) if the conn (4th) argument is NULL. Thus ret may be -ENODEV in which case the code in question will execute. Conclusion: * cp may be NULL at the point where this patch adds a check; this patch does seem to address a possible bug

• CWE-476NULL Pointer DereferenceThe product dereferences a pointer that it expects to be valid but is NULL.