ACPICA: Fix possible buffer overflow during a field unit read operation

Can only happen under these conditions: 1) The DSDT version is 1,
meaning integers are 32-bits.  2) The field is between 33 and 64
bits long.

It applies cleanly back to ACPICA 20100806+ (Linux v2.6.37+).

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: 2.6.37+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Bob Moore 2013-05-08 04:01:15 +00:00 committed by Rafael J. Wysocki
parent 371deb9500
commit 61388f9e5d

View file

@ -720,7 +720,19 @@ acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
if ((obj_desc->common_field.start_field_bit_offset == 0) &&
(obj_desc->common_field.bit_length == access_bit_width)) {
status = acpi_ex_field_datum_io(obj_desc, 0, buffer, ACPI_READ);
if (buffer_length >= sizeof(u64)) {
status =
acpi_ex_field_datum_io(obj_desc, 0, buffer,
ACPI_READ);
} else {
/* Use raw_datum (u64) to handle buffers < 64 bits */
status =
acpi_ex_field_datum_io(obj_desc, 0, &raw_datum,
ACPI_READ);
ACPI_MEMCPY(buffer, &raw_datum, buffer_length);
}
return_ACPI_STATUS(status);
}