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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>
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1 parent 9fa7347 commit 822bfa51ce44f2c63c300fdb76dc99c4d5a5ca9f Dan Carpenter committed with axboe Feb 6, 2012
Showing with 1 addition and 7 deletions.
  1. +1 −7 drivers/cdrom/cdrom.c
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8 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)
@@ -2132,15 +2127,14 @@ 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;
}
ubuf += CD_FRAMESIZE_RAW * nr;
nframes -= nr;
lba += nr;
}
-out:
kfree(cgc.buffer);
return ret;
}

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