DMA transactions which are targeted at input buffers used for the FwBlockServiceSmm software SMI handler could cause SMRAM corruption through a TOCTOU attack. DMA transactions which are targeted at input buffers used for the software SMI handler used by the FwBlockServiceSmm driver could cause SMRAM corruption through a TOCTOU attack. This issue was discovered by Insyde engineering based on the general description provided by Intels iSTARE group. Fixed in kernel 5.2: 05.27.23, 5.3: 05.36.23, 5.4: 05.44.23, 5.5: 05.52.23 https://www.insyde.com/security-pledge/SA-2022048
Weakness
The product checks the state of a resource before using that resource, but the resource’s state can change between the check and the use in a way that invalidates the results of the check.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Kernel | Insyde | 5.2 (including) | 5.2.05.27.23 (excluding) |
| Kernel | Insyde | 5.3 (including) | 5.3.05.36.23 (excluding) |
| Kernel | Insyde | 5.4 (including) | 5.4.05.44.23 (excluding) |
| Kernel | Insyde | 5.5 (including) | 5.5.05.52.23 (excluding) |