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>
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 55eaf47..8fefe59 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2119,11 +2119,6 @@
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 @@
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 @@
nframes -= nr;
lba += nr;
}
-out:
kfree(cgc.buffer);
return ret;
}