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cdrom: use copy_to_user() without the underscores

"nframes" comes from the user and "nframes * CD_FRAMESIZE_RAW" can wrap
on 32 bit systems.  That would have been ok if we used the same wrapped
value for the copy, but we use a shifted value.  We should just use the
checked version of copy_to_user() because it's not going to make a
difference to the speed.

Cc: stable@vger.kernel.com
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Dan Carpenter 13 years ago
parent
commit
822bfa51ce
1 changed files with 1 additions and 7 deletions
  1. 1 7
      drivers/cdrom/cdrom.c

+ 1 - 7
drivers/cdrom/cdrom.c

@@ -2119,11 +2119,6 @@ static int cdrom_read_cdda_old(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 	if (!nr)
 		return -ENOMEM;
 
-	if (!access_ok(VERIFY_WRITE, ubuf, nframes * CD_FRAMESIZE_RAW)) {
-		ret = -EFAULT;
-		goto out;
-	}
-
 	cgc.data_direction = CGC_DATA_READ;
 	while (nframes > 0) {
 		if (nr > nframes)
@@ -2132,7 +2127,7 @@ static int cdrom_read_cdda_old(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 		ret = cdrom_read_block(cdi, &cgc, lba, nr, 1, CD_FRAMESIZE_RAW);
 		if (ret)
 			break;
-		if (__copy_to_user(ubuf, cgc.buffer, CD_FRAMESIZE_RAW * nr)) {
+		if (copy_to_user(ubuf, cgc.buffer, CD_FRAMESIZE_RAW * nr)) {
 			ret = -EFAULT;
 			break;
 		}
@@ -2140,7 +2135,6 @@ static int cdrom_read_cdda_old(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 		nframes -= nr;
 		lba += nr;
 	}
-out:
 	kfree(cgc.buffer);
 	return ret;
 }