提交 822bfa51 编写于 作者: D Dan Carpenter 提交者: Jens Axboe

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: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
上级 9fa73472
......@@ -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;
}
......
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