[PATCH 13/18] ACPICA: Resources: Not a valid resource if buffer length too long

From: Lv Zheng
Date: Wed Dec 28 2016 - 02:29:38 EST


From: Bob Moore <robert.moore@xxxxxxxxx>

ACPICA commit 9f76de2d249b18804e35fb55d14b1c2604d627a1
ACPICA commit b2e89d72ef1e9deefd63c3fd1dee90f893575b3a
ACPICA commit 23b5bbe6d78afd3c5abf3adb91a1b098a3000b2e

The declared buffer length must be the same as the length of the
byte initializer list, otherwise not a valid resource descriptor.

Link: https://github.com/acpica/acpica/commit/9f76de2d
Link: https://github.com/acpica/acpica/commit/b2e89d72
Link: https://github.com/acpica/acpica/commit/23b5bbe6
Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx>
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
drivers/acpi/acpica/utresrc.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/acpica/utresrc.c b/drivers/acpi/acpica/utresrc.c
index 1de3376..2ad99ea 100644
--- a/drivers/acpi/acpica/utresrc.c
+++ b/drivers/acpi/acpica/utresrc.c
@@ -421,8 +421,10 @@ acpi_ut_walk_aml_resources(struct acpi_walk_state *walk_state,

ACPI_FUNCTION_TRACE(ut_walk_aml_resources);

- /* The absolute minimum resource template is one end_tag descriptor */
-
+ /*
+ * The absolute minimum resource template is one end_tag descriptor.
+ * However, we will treat a lone end_tag as just a simple buffer.
+ */
if (aml_length < sizeof(struct aml_resource_end_tag)) {
return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
}
@@ -454,9 +456,8 @@ acpi_ut_walk_aml_resources(struct acpi_walk_state *walk_state,
/* Invoke the user function */

if (user_function) {
- status =
- user_function(aml, length, offset, resource_index,
- context);
+ status = user_function(aml, length, offset,
+ resource_index, context);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
@@ -480,6 +481,12 @@ acpi_ut_walk_aml_resources(struct acpi_walk_state *walk_state,
*context = aml;
}

+ /* Check if buffer is defined to be longer than the resource length */
+
+ if (aml_length > (offset + length)) {
+ return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
+ }
+
/* Normal exit */

return_ACPI_STATUS(AE_OK);
--
2.7.4