In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer adm1266_pmbus_block_xfer() sets up the read transaction with .buf = data->read_buf, .len = ADM1266_PMBUS_BLOCK_MAX + 2, but read_buf in struct adm1266_data is declared as u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1]; For a max-length block response (length byte = 255 + up to 1 PEC byte), the i2c controller is told to write 257 bytes into a 256-byte buff
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer
adm1266_pmbus_block_xfer() sets up the read transaction with
.buf = data->read_buf,
.len = ADM1266_PMBUS_BLOCK_MAX + 2,
but read_buf in struct adm1266_data is declared as
u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1];
For a max-length block response (length byte = 255 + up to 1 PEC byte), the i2c controller is told to write 257 bytes into a 256-byte buffer, putting one byte past the end of read_buf. The same response also makes the subsequent PEC compare
if (crc != msgs[1].buf[msgs[1].buf[0] + 1])
read a byte beyond the array.
Bump the read_buf declaration to ADM1266_PMBUS_BLOCK_MAX + 2 so the buffer can hold the length byte, up to 255 payload bytes, and the PEC byte the i2c_msg length already accounts for.
Why this VPI (explainable, experimental)
VPI breakdown
| Impact(default (no data)) | 55.00 |
| Exploitation signal(No additional exploitation signal) | ×1.00 |
| VPI | 55.00 |
VPI formula vpi-v1