Patch "ACPICA: Disassembler: Abort on an invalid/unknown AML opcode" has been added to the 4.4-stable tree

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

ACPICA: Disassembler: Abort on an invalid/unknown AML opcode

to the 4.4-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-disassembler-abort-on-an-invalid-unknown-aml-opcode.patch
and it can be found in the queue-4.4 subdirectory.

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

From: Bob Moore <[email protected]>
Date: Mon, 5 Jun 2017 16:40:34 +0800
Subject: ACPICA: Disassembler: Abort on an invalid/unknown AML opcode

From: Bob Moore <[email protected]>

[ Upstream commit 6f0527b77d9e0129dd8e50945b0d610ed943d6b2 ]

ACPICA commit ed0389cb11a61e63c568ac1f67948fc6a7bd1aeb

An invalid opcode indicates something seriously wrong with the input AML file. The AML parser is immediately confused and lost, causing the resulting parse tree to be ill-formed. The actual disassembly can then cause numerous unrelated errors and faults.

This change aborts the disassembly upon discovery of such an opcode during the AML parse phase.

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

@@ -121,6 +121,9 @@ static acpi_status acpi_ps_get_aml_opcod
 			     (u32)(aml_offset +
 				   sizeof(struct acpi_table_header)));
 
+			ACPI_ERROR((AE_INFO,
+				    "Aborting disassembly, AML byte code is corrupt"));
+
 			/* Dump the context surrounding the invalid opcode */
 
 			acpi_ut_dump_buffer(((u8 *)walk_state->parser_state.

@@ -129,6 +132,14 @@ static acpi_status acpi_ps_get_aml_opcod
 					     sizeof(struct acpi_table_header) -
 					     16));
 			acpi_os_printf(" */\n");
+
+			/*
+			 * Just abort the disassembly, cannot continue because the
+			 * parser is essentially lost. The disassembler can then
+			 * randomly fail because an ill-constructed parse tree
+			 * can result.
+			 */
+			return_ACPI_STATUS(AE_AML_BAD_OPCODE);
 #endif
 		}
 

@@ -293,6 +304,9 @@ acpi_ps_create_op(struct acpi_walk_state
 	if (status == AE_CTRL_PARSE_CONTINUE) {
 		return_ACPI_STATUS(AE_CTRL_PARSE_CONTINUE);
 	}
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
 
 	/* Create Op structure and append to parent's argument list */
 

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

queue-4.4/acpica-disassembler-abort-on-an-invalid-unknown-aml-opcode.patch queue-4.4/acpica-events-add-runtime-stub-support-for-event-apis.patch