Commit 60085c3d authored Apr 07, 2013 by Mathias Krause Committed by David S. Miller Apr 07, 2013

tipc: fix info leaks via msg_name in recv_msg/recv_stream

The code in set_orig_addr() does not initialize all of the members of
struct sockaddr_tipc when filling the sockaddr info -- namely the union
is only partly filled. This will make recv_msg() and recv_stream() --
the only users of this function -- leak kernel stack memory as the
msg_name member is a local variable in net/socket.c.

Additionally to that both recv_msg() and recv_stream() fail to update
the msg_namelen member to 0 while otherwise returning with 0, i.e.
"success". This is the case for, e.g., non-blocking sockets. This will
lead to a 128 byte kernel stack leak in net/socket.c.

Fix the first issue by initializing the memory of the union with
memset(0). Fix the second one by setting msg_namelen to 0 early as it
will be updated later if we're going to fill the msg_name member.

Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 4a184233

net/tipc/socket.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -790,6 +790,7 @@ static void set_orig_addr(struct msghdr m, struct tipc_msg msg)
		if (addr) {
		addr->family = AF_TIPC;
		addr->addrtype = TIPC_ADDR_ID;
		memset(&addr->addr, 0, sizeof(addr->addr));
		addr->addr.id.ref = msg_origport(msg);
		addr->addr.id.node = msg_orignode(msg);
		addr->addr.name.domain = 0; /* could leave uninitialized */
		@@ -904,6 +905,9 @@ static int recv_msg(struct kiocb iocb, struct socket sock,
		goto exit;
		}

		/* will be updated in set_orig_addr() if needed */
		m->msg_namelen = 0;

		timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
		restart:

		@@ -1013,6 +1017,9 @@ static int recv_stream(struct kiocb iocb, struct socket sock,
		goto exit;
		}

		/* will be updated in set_orig_addr() if needed */
		m->msg_namelen = 0;

		target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len);
		timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);

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