An issue was discovered in IdeBusDxe in Insyde InsydeH2O with kernel 5.1 before 05.16.25, 5.2 before 05.26.25, 5.3 before 05.35.25, 5.4 before 05.43.25, and 5.5 before 05.51.25. A vulnerability exists in the SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointer (the status code saved at the CommBuffer+4 location).
https://www.insyde.com/security-pledge
https://security.netapp.com/advisory/ntap-20220216-0004/
https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf