[PATCH next] driver core: Replace strcpy() with memcpy()

[david.laight.linux@gmail.com]

From: David Laight <david.laight.linux@gmail.com>

The length of the string is calculated in order to allocate the correct
sized memory block, use the same length to copy the string.

Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
This is one of a group of patches that remove potentially unbounded
strcpy() calls.

They are mostly replaced by strscpy() or, when strlen() has just been
called, with memcpy() (usually including the '\0').

Calls with copy string literals into arrays are left unchanged.
They are safe and easily detected as such.

The changes were made by getting the compiler to detect the calls and
then fixing the code by hand.

Note that all the changes are only compile tested.

Some Makefiles were changed to allow files to contain strcpy().
As well as 'difficult to fix' files, this included 'show' functions
as they really need to use sysfs_emit() or seq_printf().

All the patches are being sent individually to avoid very long cc lists.
Apologies for the terse commit messages and likely unexpected tags.
(There are about 100 patches in total.)

 drivers/firmware/dmi_scan.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index a3f7dabd4955..870767142b53 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -80,7 +80,7 @@ static const char * __init dmi_string(const struct dmi_header *dm, u8 s)
 	len = strlen(bp) + 1;
 	str = dmi_alloc(len);
 	if (str != NULL)
-		strcpy(str, bp);
+		memcpy(str, bp, len);
 
 	return str;
 }
@@ -290,17 +290,19 @@ static void __init dmi_save_type(const struct dmi_header *dm, int slot,
 static void __init dmi_save_one_device(int type, const char *name)
 {
 	struct dmi_device *dev;
+	size_t len;
 
 	/* No duplicate device */
 	if (dmi_find_device(type, name, NULL))
 		return;
 
-	dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
+	len = strlen(name) + 1;
+	dev = dmi_alloc(sizeof(*dev) + len);
 	if (!dev)
 		return;
 
 	dev->type = type;
-	strcpy((char *)(dev + 1), name);
+	memcpy((char *)(dev + 1), name, len);
 	dev->name = (char *)(dev + 1);
 	dev->device_data = NULL;
 	list_add(&dev->list, &dmi_devices);
@@ -374,13 +376,15 @@ static void __init dmi_save_dev_pciaddr(int instance, int segment, int bus,
 					int devfn, const char *name, int type)
 {
 	struct dmi_dev_onboard *dev;
+	size_t len;
 
 	/* Ignore invalid values */
 	if (type == DMI_DEV_TYPE_DEV_SLOT &&
 	    segment == 0xFFFF && bus == 0xFF && devfn == 0xFF)
 		return;
 
-	dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
+	len = strlen(name) + 1;
+	dev = dmi_alloc(sizeof(*dev) + len);
 	if (!dev)
 		return;
 
@@ -389,7 +393,7 @@ static void __init dmi_save_dev_pciaddr(int instance, int segment, int bus,
 	dev->bus = bus;
 	dev->devfn = devfn;
 
-	strcpy((char *)&dev[1], name);
+	memcpy((char *)&dev[1], name, len);
 	dev->dev.type = type;
 	dev->dev.name = (char *)&dev[1];
 	dev->dev.device_data = dev;
-- 
2.39.5