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cdrom: use copy_to_user() without the underscores

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"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>
This commit is contained in:
Dan Carpenter 2012-02-06 10:20:45 +01:00 committed by Jens Axboe
parent 9fa73472dd
commit 822bfa51ce
1 changed files with 1 additions and 7 deletions
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8
drivers/cdrom/cdrom.c
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@ -2119,11 +2119,6 @@ static int cdrom_read_cdda_old(struct cdrom_device_info *cdi, __u8 __user *ubuf,
if (!nr) if (!nr)
return -ENOMEM; return -ENOMEM;
if (!access_ok(VERIFY_WRITE, ubuf, nframes * CD_FRAMESIZE_RAW)) {
ret = -EFAULT;
goto out;
}
cgc.data_direction = CGC_DATA_READ; cgc.data_direction = CGC_DATA_READ;
while (nframes > 0) { while (nframes > 0) {
if (nr > nframes) 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); ret = cdrom_read_block(cdi, &cgc, lba, nr, 1, CD_FRAMESIZE_RAW);
if (ret) if (ret)
break; 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; ret = -EFAULT;
break; break;
} }
@ -2140,7 +2135,6 @@ static int cdrom_read_cdda_old(struct cdrom_device_info *cdi, __u8 __user *ubuf,
nframes -= nr; nframes -= nr;
lba += nr; lba += nr;
} }
out:
kfree(cgc.buffer); kfree(cgc.buffer);
return ret; return ret;
} }