cdrom: don't open-code memdup_user()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index c206ccda899b388fe7856424078c505f99c87830..1b257ea9776ae596ed3164bc11a37d325c47d989 100644 (file)
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -3186,15 +3186,11 @@ static noinline int mmc_ioctl_dvd_read_struct(struct cdrom_device_info *cdi,
        if (!CDROM_CAN(CDC_DVD))
                return -ENOSYS;
 
-       s = kmalloc(size, GFP_KERNEL);
-       if (!s)
-               return -ENOMEM;
+       s = memdup_user(arg, size);
+       if (IS_ERR(s))
+               return PTR_ERR(s);
 
        cd_dbg(CD_DO_IOCTL, "entering DVD_READ_STRUCT\n");
-       if (copy_from_user(s, arg, size)) {
-               kfree(s);
-               return -EFAULT;
-       }
 
        ret = dvd_read_struct(cdi, s, cgc);
        if (ret)