From: Wei Liu <wei.liu2@citrix.com>
Date: Wed, 1 Mar 2017 11:07:24 +0000 (+0000)
Subject: acpi: check if mapping is valid before reading / writing
X-Git-Tag: 4.9.0-rc1~367
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=34b05462d93f06f9a08caf98b7aed865f6b796bd;p=xen.git

acpi: check if mapping is valid before reading / writing

If acpi_map_os_memory has failed, return early with AE_ERROR.

Coverity-ID: 1401601
Coverity-ID: 1401602

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---

diff --git a/xen/drivers/acpi/osl.c b/xen/drivers/acpi/osl.c
index 94dbf0406f..9881db19da 100644
--- a/xen/drivers/acpi/osl.c
+++ b/xen/drivers/acpi/osl.c
@@ -155,6 +155,9 @@ acpi_os_read_memory(acpi_physical_address phys_addr, u32 * value, u32 width)
 	u32 dummy;
 	void __iomem *virt_addr = acpi_os_map_memory(phys_addr, width >> 3);
 
+	if (!virt_addr)
+		return AE_ERROR;
+
 	if (!value)
 		value = &dummy;
 
@@ -182,6 +185,9 @@ acpi_os_write_memory(acpi_physical_address phys_addr, u32 value, u32 width)
 {
 	void __iomem *virt_addr = acpi_os_map_memory(phys_addr, width >> 3);
 
+	if (!virt_addr)
+		return AE_ERROR;
+
 	switch (width) {
 	case 8:
 		writeb(value, virt_addr);