3 files changed, 53 insertions, 15 deletions

diff --git a/arch/sparc64/kernel/vio.c b/arch/sparc64/kernel/vio.c
index 64f082555bcd..8b269aabff07 100644
--- a/arch/sparc64/kernel/vio.c
+++ b/arch/sparc64/kernel/vio.c
@@ -44,12 +44,11 @@ static const struct vio_device_id *vio_match_device(
 
         while (matches->type[0] || matches->compat[0]) {
                 int match = 1;
-                if (matches->type[0]) {
-                        match &= type
-                                && !strcmp(matches->type, type);
-                }
+                if (matches->type[0])
+                        match &= !strcmp(matches->type, type);
+
                 if (matches->compat[0]) {
-                        match &= compat &&
+                        match &= len &&
                                 find_in_proplist(compat, matches->compat, len);
                 }
                 if (match)
@@ -205,15 +204,30 @@ static struct vio_dev *vio_create_one(struct mdesc_handle *hp, u64 mp,
         const char *type, *compat;
         struct device_node *dp;
         struct vio_dev *vdev;
-        int err, clen;
+        int err, tlen, clen;
 
-        type = mdesc_get_property(hp, mp, "device-type", NULL);
+        type = mdesc_get_property(hp, mp, "device-type", &tlen);
         if (!type) {
-                type = mdesc_get_property(hp, mp, "name", NULL);
-                if (!type)
+                type = mdesc_get_property(hp, mp, "name", &tlen);
+                if (!type) {
                         type = mdesc_node_name(hp, mp);
+                        tlen = strlen(type) + 1;
+                }
+        }
+        if (tlen > VIO_MAX_TYPE_LEN) {
+                printk(KERN_ERR "VIO: Type string [%s] is too long.\n",
+                       type);
+                return NULL;
         }
+
         compat = mdesc_get_property(hp, mp, "device-type", &clen);
+        if (!compat) {
+                clen = 0;
+        } else if (clen > VIO_MAX_COMPAT_LEN) {
+                printk(KERN_ERR "VIO: Compat len %d for [%s] is too long.\n",
+                       clen, type);
+                return NULL;
+        }
 
         vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
         if (!vdev) {
@@ -222,8 +236,11 @@ static struct vio_dev *vio_create_one(struct mdesc_handle *hp, u64 mp,
         }
 
         vdev->mp = mp;
-        vdev->type = type;
-        vdev->compat = compat;
+        memcpy(vdev->type, type, tlen);
+        if (compat)
+                memcpy(vdev->compat, compat, clen);
+        else
+                memset(vdev->compat, 0, sizeof(vdev->compat));
         vdev->compat_len = clen;
 
         vdev->channel_id = ~0UL;
diff --git a/include/asm-sparc64/mdesc.h b/include/asm-sparc64/mdesc.h
index bbb0c0bed486..dc372df23fb3 100644
--- a/include/asm-sparc64/mdesc.h
+++ b/include/asm-sparc64/mdesc.h
@@ -23,8 +23,28 @@ extern u64 mdesc_node_by_name(struct mdesc_handle *handle,
              (__node) != MDESC_NODE_NULL; \
              __node = mdesc_node_by_name(__hdl, __node, __name))
 
+/* Access to property values returned from mdesc_get_property() are
+ * only valid inside of a mdesc_grab()/mdesc_release() sequence.
+ * Once mdesc_release() is called, the memory backed up by these
+ * pointers may reference freed up memory.
+ *
+ * Therefore callers must make copies of any property values
+ * they need.
+ *
+ * These same rules apply to mdesc_node_name().
+ */
 extern const void *mdesc_get_property(struct mdesc_handle *handle,
                                       u64 node, const char *name, int *lenp);
+extern const char *mdesc_node_name(struct mdesc_handle *hp, u64 node);
+
+/* MD arc iteration, the standard sequence is:
+ *
+ *      unsigned long arc;
+ *      mdesc_for_each_arc(arc, handle, node, MDESC_ARC_TYPE_{FWD,BACK}) {
+ *              unsigned long target = mdesc_arc_target(handle, arc);
+ *              ...
+ *      }
+ */
 
 #define MDESC_ARC_TYPE_FWD      "fwd"
 #define MDESC_ARC_TYPE_BACK     "back"
@@ -38,8 +58,6 @@ extern u64 mdesc_next_arc(struct mdesc_handle *handle, u64 from,
 
 extern u64 mdesc_arc_target(struct mdesc_handle *hp, u64 arc);
 
-extern const char *mdesc_node_name(struct mdesc_handle *hp, u64 node);
-
 extern void mdesc_update(void);
 
 extern void sun4v_mdesc_init(void);
diff --git a/include/asm-sparc64/vio.h b/include/asm-sparc64/vio.h
index a8a53e6fc250..83c96422e9d6 100644
--- a/include/asm-sparc64/vio.h
+++ b/include/asm-sparc64/vio.h
@@ -264,12 +264,15 @@ static inline u32 vio_dring_avail(struct vio_dring_state *dr,
                 ((dr->prod - dr->cons) & (ring_size - 1)));
 }
 
+#define VIO_MAX_TYPE_LEN        64
+#define VIO_MAX_COMPAT_LEN      64
+
 struct vio_dev {
         u64                     mp;
         struct device_node      *dp;
 
-        const char              *type;
-        const char              *compat;
+        char                    type[VIO_MAX_TYPE_LEN];
+        char                    compat[VIO_MAX_COMPAT_LEN];
         int                     compat_len;
 
         unsigned long           channel_id;