DMA attacks on the parameter buffer used by the Int15ServiceSmm software SMI handler could lead to a TOCTOU attack on the SMI handler and lead to corruption of SMRAM. DMA attacks on the parameter buffer used by the software SMI handler used by the driver Int15ServiceSmm could lead to a TOCTOU attack on the SMI handler and lead to corruption of SMRAM. This issue was discovered by Insyde engineering during a security review. This issue is fixed in Kernel 5.2: 05.27.23, Kernel 5.3: 05.36.23, Kernel 5.4: 05.44.23 and Kernel 5.5: 05.52.23 CWE-367