This is a note to let you know that I've just added the patch titled

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

to the 3.9-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     
acpica-fix-possible-buffer-overflow-during-a-field-unit-read-operation.patch
and it can be found in the queue-3.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 61388f9e5d93053cf399a356414f31f9b4814c6d Mon Sep 17 00:00:00 2001
From: Bob Moore <[email protected]>
Date: Wed, 8 May 2013 04:01:15 +0000
Subject: ACPICA: Fix possible buffer overflow during a field unit read operation

From: Bob Moore <[email protected]>

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 <[email protected]>
Signed-off-by: Lv Zheng <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/acpi/acpica/exfldio.c |   14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

--- a/drivers/acpi/acpica/exfldio.c
+++ b/drivers/acpi/acpica/exfldio.c
@@ -720,7 +720,19 @@ acpi_ex_extract_from_field(union acpi_op
 
        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);
        }
 


Patches currently in stable-queue which might be from [email protected] are

queue-3.9/acpica-fix-possible-buffer-overflow-during-a-field-unit-read-operation.patch
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