[Spice-devel] [PATCH spice-server 3/3] main-channel: Prevent overflow reading messages from client

[Frediano Ziglio]

Caller is supposed the function return a buffer able to store
size bytes.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
Acked-by: Christophe Fergeau <cfergeau at redhat.com>
---
 server/main-channel.c | 3 +++
 1 file changed, 3 insertions(+)

This patch was developed and reviewed internally for security reasons.

diff --git a/server/main-channel.c b/server/main-channel.c
index 24dd448..1124506 100644
--- a/server/main-channel.c
+++ b/server/main-channel.c
@@ -258,6 +258,9 @@ static uint8_t *main_channel_alloc_msg_rcv_buf(RedChannelClient *rcc,
 
     if (type == SPICE_MSGC_MAIN_AGENT_DATA) {
         return reds_get_agent_data_buffer(red_channel_get_server(channel), mcc, size);
+    } else if (size > sizeof(main_chan->recv_buf)) {
+        /* message too large, caller will log a message and close the connection */
+        return NULL;
     } else {
         return main_chan->recv_buf;
     }
-- 
2.9.3