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authorBob Moore <robert.moore@intel.com>2013-05-08 04:01:15 +0000
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-05-08 15:31:37 +0200
commit61388f9e5d93053cf399a356414f31f9b4814c6d (patch)
treef50814ce10be2256c65aeb83dbd4482733486fff /drivers
parent371deb9500831ad1afbf9ea00e373f650deaed2f (diff)
downloadvexpress-lsk-61388f9e5d93053cf399a356414f31f9b4814c6d.tar.gz
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/acpi/acpica/exfldio.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/acpi/acpica/exfldio.c b/drivers/acpi/acpica/exfldio.c
index ec7f5690031..c84ee956fa4 100644
--- a/drivers/acpi/acpica/exfldio.c
+++ b/drivers/acpi/acpica/exfldio.c
@@ -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);
}