From 94adafe60f4a1ed621da67dde6cc457fd5255e18 Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Wed, 8 May 2013 04:01:15 +0000 Subject: ACPICA: Fix possible buffer overflow during a field unit read operation commit 61388f9e5d93053cf399a356414f31f9b4814c6d upstream. 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 Signed-off-by: Lv Zheng Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/acpica/exfldio.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/acpica/exfldio.c b/drivers/acpi/acpica/exfldio.c index f915a7f..b334f54 100644 --- a/drivers/acpi/acpica/exfldio.c +++ b/drivers/acpi/acpica/exfldio.c @@ -702,7 +702,19 @@ 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); } -- cgit v1.1