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Commit 61388f9e authored by Bob Moore's avatar Bob Moore Committed by Rafael J. Wysocki
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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: default avatarBob Moore <robert.moore@intel.com>
Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
Cc: 2.6.37+ <stable@vger.kernel.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 371deb95

drivers/acpi/acpica/exfldio.c

+13 −1
Original line number Original line Diff line number Diff line
@@ -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) &&

	if ((obj_desc->common_field.start_field_bit_offset == 0) &&

	    (obj_desc->common_field.bit_length == access_bit_width)) {

	    (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);

		return_ACPI_STATUS(status);

	}

	}