[04/65] ACPICA: Fix possible buffer overflow during a field unit read operation

Steven Rostedt
2013-06-03T22:12:29Z

[-- Attachment #1: 0004-ACPICA-Fix-possible-buffer-overflow-during-a-field-u.patch --]
[-- Type: text/plain, Size: 1623 bytes --]

3.6.11.5 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Bob Moore <robert.moore@intel.com>

[ Upstream commit 61388f9e5d93053cf399a356414f31f9b4814c6d ]

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>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
drivers/acpi/acpica/exfldio.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/acpica/exfldio.c b/drivers/acpi/acpica/exfldio.c
index a778415..d5d9bf0 100644
--- a/drivers/acpi/acpica/exfldio.c
+++ b/drivers/acpi/acpica/exfldio.c
@@ -722,7 +722,19 @@ 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);
}

--
1.7.10.4