| From | Kamal Mostafa <> | Subject | [PATCH 20/78] ACPICA: Fix possible buffer overflow during a field unit read operation | Date | Tue, 28 May 2013 14:19:29 -0700 |
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3.8.13.1 -stable review patch. If anyone has any objections, please let me know.
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From: Bob Moore <robert.moore@intel.com>
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 <robert.moore@intel.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- 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 aa2ccfb..142fdd0 100644 --- a/drivers/acpi/acpica/exfldio.c +++ b/drivers/acpi/acpica/exfldio.c @@ -721,7 +721,19 @@ 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); } -- 1.8.1.2
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