[patch 17/47] can: Fix copy_from_user() results interpretation

Greg KH
2008-06-14T00:17:55Z

[-- Attachment #1: can-fix-copy_from_user-results-interpretation.patch --]
[-- Type: text/plain, Size: 2062 bytes --]

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

------------------
From: Sam Ravnborg <sam@ravnborg.org>

[ Upstream commit: 3f91bd420a955803421f2db17b2e04aacfbb2bb8 ]

Both copy_to_ and _from_user return the number of bytes, that failed to
reach their destination, not the 0/-EXXX values.

Based on patch from Pavel Emelyanov <xemul@openvz.org>

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---
net/can/raw.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)

--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -435,15 +435,13 @@ static int raw_setsockopt(struct socket
if (!filter)
return -ENOMEM;

- err = copy_from_user(filter, optval, optlen);
- if (err) {
+ if (copy_from_user(filter, optval, optlen)) {
kfree(filter);
- return err;
+ return -EFAULT;
}
} else if (count == 1) {
- err = copy_from_user(&sfilter, optval, optlen);
- if (err)
- return err;
+ if (copy_from_user(&sfilter, optval, optlen))
+ return -EFAULT;
}

lock_sock(sk);
@@ -493,9 +491,8 @@ static int raw_setsockopt(struct socket
if (optlen != sizeof(err_mask))
return -EINVAL;

- err = copy_from_user(&err_mask, optval, optlen);
- if (err)
- return err;
+ if (copy_from_user(&err_mask, optval, optlen))
+ return -EFAULT;

err_mask &= CAN_ERR_MASK;

@@ -531,7 +528,8 @@ static int raw_setsockopt(struct socket
if (optlen != sizeof(ro->loopback))
return -EINVAL;

- err = copy_from_user(&ro->loopback, optval, optlen);
+ if (copy_from_user(&ro->loopback, optval, optlen))
+ return -EFAULT;

break;

@@ -539,7 +537,8 @@ static int raw_setsockopt(struct socket
if (optlen != sizeof(ro->recv_own_msgs))
return -EINVAL;

- err = copy_from_user(&ro->recv_own_msgs, optval, optlen);
+ if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
+ return -EFAULT;

break;

--