rxrpc: bogus MSG_PEEK test in rxrpc_recvmsg()

[ Upstream commit 7d985ed1dca5c90535d67ce92ef6ca520302340a ]

[I would really like an ACK on that one from dhowells; it appears to be
quite straightforward, but...]

MSG_PEEK isn't passed to ->recvmsg() via msg->msg_flags; as the matter of
fact, neither the kernel users of rxrpc, nor the syscalls ever set that bit
in there.  It gets passed via flags; in fact, another such check in the same
function is done correctly - as flags & MSG_PEEK.

It had been that way (effectively disabled) for 8 years, though, so the patch
needs beating up - that case had never been tested.  If it is correct, it's
-stable fodder.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/rxrpc/ar-recvmsg.c b/net/rxrpc/ar-recvmsg.c
index 898492a8d61be8fde5bcdf66084d525bee23b5f0..5cc2da5d295d727e6346c51eceae8e0211b7ceb9 100644 (file)
--- a/net/rxrpc/ar-recvmsg.c
+++ b/net/rxrpc/ar-recvmsg.c
@@ -87,7 +87,7 @@ int rxrpc_recvmsg(struct kiocb *iocb, struct socket *sock,
                if (!skb) {
                        /* nothing remains on the queue */
                        if (copied &&
-                           (msg->msg_flags & MSG_PEEK || timeo == 0))
+                           (flags & MSG_PEEK || timeo == 0))
                                goto out;
 
                        /* wait for a message to turn up */