[09/37] net: Fix wrong interpretation of some copy_to_user()results.

[Greg KH]

2.6.25-stable review patch.  If anyone has any objections, please let us
know.

------------------
From: Pavel Emelyanov <xemul@xxxxxxxxxx>

[ Upstream commit: 653252c2302cdf2dfbca66a7e177f7db783f9efa ]

I found some places, that erroneously return the value obtained from
the copy_to_user() call: if some amount of bytes were not able to get
to the user (this is what this one returns) the proper behavior is to
return the -EFAULT error, not that number itself.

Signed-off-by: Pavel Emelyanov <xemul@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 net/can/raw.c     |    3 ++-
 net/dccp/probe.c  |    2 +-
 net/tipc/socket.c |    4 ++--
 3 files changed, 5 insertions(+), 4 deletions(-)

--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -573,7 +573,8 @@ static int raw_getsockopt(struct socket 
 			int fsize = ro->count * sizeof(struct can_filter);
 			if (len > fsize)
 				len = fsize;
-			err = copy_to_user(optval, ro->filter, len);
+			if (copy_to_user(optval, ro->filter, len))
+				err = -EFAULT;
 		} else
 			len = 0;
 		release_sock(sk);
--- a/net/dccp/probe.c
+++ b/net/dccp/probe.c
@@ -145,7 +145,7 @@ static ssize_t dccpprobe_read(struct fil
 		goto out_free;
 
 	cnt = kfifo_get(dccpw.fifo, tbuf, len);
-	error = copy_to_user(buf, tbuf, cnt);
+	error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0;
 
 out_free:
 	vfree(tbuf);
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1600,8 +1600,8 @@ static int getsockopt(struct socket *soc
 	else if (len < sizeof(value)) {
 		res = -EINVAL;
 	}
-	else if ((res = copy_to_user(ov, &value, sizeof(value)))) {
-		/* couldn't return value */
+	else if (copy_to_user(ov, &value, sizeof(value))) {
+		res = -EFAULT;
 	}
 	else {
 		res = put_user(sizeof(value), ol);

-- 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/