3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: "Yan, Zheng" <redacted>

(cherry picked from commit 43643528cce60ca184fe8197efa8e8da7c89a037)
(cherry picked from commit b132cf4c733f91bb4dd2277ea049243cf16e8b66)

The bug can cause NULL pointer dereference in write_partial_msg_pages

Signed-off-by: Zheng Yan <redacted>
Reviewed-by: Alex Elder <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ceph/messenger.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c

@@ -563,6 +563,10 @@ static void prepare_write_message(struct
 		m->hdr.seq = cpu_to_le64(++con->out_seq);
 		m->needs_out_seq = false;
 	}
+#ifdef CONFIG_BLOCK
+	else
+		m->bio_iter = NULL;
+#endif
 
 	dout("prepare_write_message %p seq %lld type %d len %d+%d+%d %d pgs\n",
 	     m, con->out_seq, le16_to_cpu(m->hdr.type),