1 files changed, 46 insertions, 20 deletions

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index e0694e4d86c7..5f3a52d517c3 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -167,13 +167,9 @@ static ssize_t i2cdev_write(struct file *file, const char __user *buf,
         if (count > 8192)
                 count = 8192;
 
-        tmp = kmalloc(count, GFP_KERNEL);
-        if (tmp == NULL)
-                return -ENOMEM;
-        if (copy_from_user(tmp, buf, count)) {
-                kfree(tmp);
-                return -EFAULT;
-        }
+        tmp = memdup_user(buf, count);
+        if (IS_ERR(tmp))
+                return PTR_ERR(tmp);
 
         pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
                 iminor(file->f_path.dentry->d_inode), count);
@@ -193,12 +189,50 @@ static int i2cdev_check(struct device *dev, void *addrp)
         return dev->driver ? -EBUSY : 0;
 }
 
+/* walk up mux tree */
+static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
+{
+        int result;
+
+        result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
+
+        if (!result && i2c_parent_is_i2c_adapter(adapter))
+                result = i2cdev_check_mux_parents(
+                                    to_i2c_adapter(adapter->dev.parent), addr);
+
+        return result;
+}
+
+/* recurse down mux tree */
+static int i2cdev_check_mux_children(struct device *dev, void *addrp)
+{
+        int result;
+
+        if (dev->type == &i2c_adapter_type)
+                result = device_for_each_child(dev, addrp,
+                                                i2cdev_check_mux_children);
+        else
+                result = i2cdev_check(dev, addrp);
+
+        return result;
+}
+
 /* This address checking function differs from the one in i2c-core
    in that it considers an address with a registered device, but no
    driver bound to it, as NOT busy. */
 static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
 {
-        return device_for_each_child(&adapter->dev, &addr, i2cdev_check);
+        int result = 0;
+
+        if (i2c_parent_is_i2c_adapter(adapter))
+                result = i2cdev_check_mux_parents(
+                                    to_i2c_adapter(adapter->dev.parent), addr);
+
+        if (!result)
+                result = device_for_each_child(&adapter->dev, &addr,
+                                                i2cdev_check_mux_children);
+
+        return result;
 }
 
 static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
@@ -219,9 +253,7 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
         if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
                 return -EINVAL;
 
-        rdwr_pa = (struct i2c_msg *)
-                kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
-                GFP_KERNEL);
+        rdwr_pa = kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), GFP_KERNEL);
         if (!rdwr_pa)
                 return -ENOMEM;
 
@@ -247,15 +279,9 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
                         break;
                 }
                 data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
-                rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
-                if (rdwr_pa[i].buf == NULL) {
-                        res = -ENOMEM;
-                        break;
-                }
-                if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i],
-                                   rdwr_pa[i].len)) {
-                                ++i; /* Needs to be kfreed too */
-                                res = -EFAULT;
+                rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len);
+                if (IS_ERR(rdwr_pa[i].buf)) {
+                        res = PTR_ERR(rdwr_pa[i].buf);
                         break;
                 }
         }