[PATCH net v2 3/4] rxrpc: Improve setsockopt() handling of malformed user input

[Michal Luczaj]

copy_from_sockptr() doesn't return negative value on error. Instead it's
the number of bytes that could not be copied. Turn that into EFAULT.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: Michal Luczaj <mhal at rbox.co>
---
 net/rxrpc/af_rxrpc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index f4844683e12039d636253cb06f622468593487eb..dcf64dc148cceb547ffdb1cea8ff53a0633f5c06 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -702,14 +702,14 @@ static int rxrpc_setsockopt(struct socket *sock, int level, int optname,
 
 		case RXRPC_MIN_SECURITY_LEVEL:
 			ret = -EINVAL;
-			if (optlen != sizeof(unsigned int))
+			if (optlen != sizeof(min_sec_level))
 				goto error;
 			ret = -EISCONN;
 			if (rx->sk.sk_state != RXRPC_UNBOUND)
 				goto error;
-			ret = copy_from_sockptr(&min_sec_level, optval,
-				       sizeof(unsigned int));
-			if (ret < 0)
+			ret = -EFAULT;
+			if (copy_from_sockptr(&min_sec_level, optval,
+					      sizeof(min_sec_level)))
 				goto error;
 			ret = -EINVAL;
 			if (min_sec_level > RXRPC_SECURITY_MAX)

-- 
2.46.2