DMA attacks on the parameter buffer used by the IhisiSmm driver could change the contents after parameter values have been checked but before they are used (a TOCTOU attack). DMA attacks on the parameter buffer used by the IhisiSmm driver could change the contents after parameter values have been checked but before they are used (a TOCTOU attack). This issue was discovered by Insyde engineering. This issue is fixed in Kernel 5.4: 05.44.23 and Kernel 5.5: 05.52.23. CWE-367