[PATCH v1 14/27] ACPICA: add boundary checks in acpi_ps_get_next_field()

["Rafael J. Wysocki" <rafael@kernel.org>]

From: ikaros <void0red@gmail.com>

Add boundary checks in acpi_ps_get_next_field() to prevent out-of-bounds
access.

Link: https://github.com/acpica/acpica/commit/c39183ea84bc
Signed-off-by: ikaros <void0red@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/acpica/psargs.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/acpi/acpica/psargs.c b/drivers/acpi/acpica/psargs.c
index 87d32fbba0a6..3526ea109414 100644
--- a/drivers/acpi/acpica/psargs.c
+++ b/drivers/acpi/acpica/psargs.c
@@ -491,6 +491,10 @@ static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
 	ASL_CV_CAPTURE_COMMENTS_ONLY(parser_state);
 	aml = parser_state->aml;
 
+	if (aml >= parser_state->aml_end) {
+		return_PTR(NULL);
+	}
+
 	/* Determine field type */
 
 	switch (ACPI_GET8(parser_state->aml)) {
@@ -539,6 +543,11 @@ static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
 
 		/* Get the 4-character name */
 
+		if ((parser_state->aml + ACPI_NAMESEG_SIZE) >
+		    parser_state->aml_end) {
+			acpi_ps_free_op(field);
+			return_PTR(NULL);
+		}
 		ACPI_MOVE_32_TO_32(&name, parser_state->aml);
 		acpi_ps_set_name(field, name);
 		parser_state->aml += ACPI_NAMESEG_SIZE;
@@ -584,6 +593,10 @@ static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
 
 		/* Get the two bytes (Type/Attribute) */
 
+		if ((parser_state->aml + 2) > parser_state->aml_end) {
+			acpi_ps_free_op(field);
+			return_PTR(NULL);
+		}
 		access_type = ACPI_GET8(parser_state->aml);
 		parser_state->aml++;
 		access_attribute = ACPI_GET8(parser_state->aml);
@@ -595,6 +608,10 @@ static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
 		/* This opcode has a third byte, access_length */
 
 		if (opcode == AML_INT_EXTACCESSFIELD_OP) {
+			if (parser_state->aml >= parser_state->aml_end) {
+				acpi_ps_free_op(field);
+				return_PTR(NULL);
+			}
 			access_length = ACPI_GET8(parser_state->aml);
 			parser_state->aml++;
 
-- 
2.51.0