[PATCH net v2 2/4] llc: Improve setsockopt() handling of malformed user input

[Michal Luczaj]

copy_from_sockptr()'s non-zero result represents the number of bytes that
could not be copied. Turn that into EFAULT.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Michal Luczaj <mhal at rbox.co>
---
 net/llc/af_llc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 4eb52add7103b0f83d6fe7318abf1d1af533d254..711c8a7a423f1cf1b03e684a6e23c8eefbab830f 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -1096,12 +1096,12 @@ static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
 	int rc = -EINVAL;
 
 	lock_sock(sk);
-	if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
+	if (unlikely(level != SOL_LLC || optlen != sizeof(opt)))
 		goto out;
-	rc = copy_from_sockptr(&opt, optval, sizeof(opt));
-	if (rc)
+	if (copy_from_sockptr(&opt, optval, sizeof(opt))) {
+		rc = -EFAULT;
 		goto out;
-	rc = -EINVAL;
+	}
 	switch (optname) {
 	case LLC_OPT_RETRY:
 		if (opt > LLC_OPT_MAX_RETRY)

-- 
2.46.2