[PATCH 3.2 205/221] rxrpc: bogus MSG_PEEK test in rxrpc_recvmsg()

Ben Hutchings
2015-05-05T02:23:56Z

From: Al Viro <viro@ZenIV.linux.org.uk>

[ 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: Ben Hutchings <ben@decadent.org.uk>
---
net/rxrpc/ar-recvmsg.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/rxrpc/ar-recvmsg.c
+++ b/net/rxrpc/ar-recvmsg.c
@@ -87,7 +87,7 @@ int rxrpc_recvmsg(struct kiocb *iocb, st
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 */