From: Lv Zheng <lv.zheng@intel.com>
Date: Mon, 10 Jul 2017 15:23:21 +0800
Subject: ACPICA: Tables: Add sanity check in acpi_put_table()
Patch-mainline: v4.14-rc1
Git-commit: 96d07940623a2a40b2eec01daebf93bbaaee8a3b
References: bsc#1117419

ACPICA commit 73512384c9eb1e7f1b28d0a7372df26a3732f96b

To avoid caller to trigger unexpected warning messages (Link #1):
  ACPI Warning: Table ffffffffbb461d20, Validation count is zero before decrement
Which is reported from acpi_tb_put_table(). When the table is validated, the
pointer must be non-zero. Thus the message is not suitable for invalidated
tables. This patch fixes the callee side based on this fact. Reported by
Cristian Aravena Romero, Fixed by Lv Zheng.

Link: https://github.com/acpica/acpica/commit/73512384
Link: https://bugzilla.kernel.org/show_bug.cgi?id=191221 [#1]
Reported-by: Cristian Aravena Romero <caravena@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
 drivers/acpi/acpica/tbxface.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/acpi/acpica/tbxface.c
+++ b/drivers/acpi/acpica/tbxface.c
@@ -369,6 +369,10 @@ void acpi_put_table(struct acpi_table_he
 
 	ACPI_FUNCTION_TRACE(acpi_put_table);
 
+	if (!table) {
+		return_VOID;
+	}
+
 	(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 
 	/* Walk the root table list */