summaryrefslogtreecommitdiffstats
path: root/queue-2.6.32/cdrom-use-copy_to_user-without-the-underscores.patch
blob: eba6a3369379f853d37f1d3b8408364381939cb3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
From 822bfa51ce44f2c63c300fdb76dc99c4d5a5ca9f Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Mon, 6 Feb 2012 10:20:45 +0100
Subject: cdrom: use copy_to_user() without the underscores

From: Dan Carpenter <dan.carpenter@oracle.com>

commit 822bfa51ce44f2c63c300fdb76dc99c4d5a5ca9f upstream.

"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.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/cdrom/cdrom.c |    8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2057,11 +2057,6 @@ static int cdrom_read_cdda_old(struct cd
 	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)
@@ -2070,7 +2065,7 @@ static int cdrom_read_cdda_old(struct cd
 		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;
 		}
@@ -2078,7 +2073,6 @@ static int cdrom_read_cdda_old(struct cd
 		nframes -= nr;
 		lba += nr;
 	}
-out:
 	kfree(cgc.buffer);
 	return ret;
 }