1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
From 53488f0275d6c8a121af49f7ac817d09ce68090d Mon Sep 17 00:00:00 2001
From: David Gibson <david@gibson.dropbear.id.au>
Date: Fri, 05 Jul 2013 07:11:46 +0000
Subject: Use RING_FOREACH_SAFE in red_channel.c functions which are missing it
Currently, both red_channel_pipes_add_type() and
red_channel_pipes_add_empty_msg() use plaing RING_FOREACH() which is not
safe versus removals from the ring within the loop body.
Although it's rare, such a removal can occur in both cases. In the case
of red_channel_pipes_add_type() we have:
red_channel_pipes_add_type()
-> red_channel_client_pipe_add_type()
-> red_channel_client_push()
And in the case of red_channel_client_pipes_add_empty_msg() we have:
red_channel_client_pipes_add_empty_msg()
-> red_channel_client_pipe_add_empty_msg()
-> red_channel_client_push()
But red_channel_client_push() can cause a removal from the clients ring if
a network error occurs:
red_channel_client_push()
-> red_channel_client_send()
-> red_peer_handle_outgoing()
-> handler->cb->on_error callback
= red_channel_client_default_peer_on_error()
-> red_channel_client_disconnect()
-> red_channel_remove_client()
-> ring_remove()
When this error path does occur, the assertion in RING_FOREACH()'s
ring_next() trips, and the process containing the spice server is aborted.
i.e. your whole VM dies, as a result of an unfortunately timed network
error on the spice channel.
Please apply.
Signed-off-by: David Gibson <dgibson@redhat.com>
---
diff --git a/server/red_channel.c b/server/red_channel.c
index c0b1781..8742008 100644
--- a/server/red_channel.c
+++ b/server/red_channel.c
@@ -1572,9 +1572,9 @@ void red_channel_client_pipe_add_type(RedChannelClient *rcc, int pipe_item_type)
void red_channel_pipes_add_type(RedChannel *channel, int pipe_item_type)
{
- RingItem *link;
+ RingItem *link, *next;
- RING_FOREACH(link, &channel->clients) {
+ RING_FOREACH_SAFE(link, next, &channel->clients) {
red_channel_client_pipe_add_type(
SPICE_CONTAINEROF(link, RedChannelClient, channel_link),
pipe_item_type);
@@ -1593,9 +1593,9 @@ void red_channel_client_pipe_add_empty_msg(RedChannelClient *rcc, int msg_type)
void red_channel_pipes_add_empty_msg(RedChannel *channel, int msg_type)
{
- RingItem *link;
+ RingItem *link, *next;
- RING_FOREACH(link, &channel->clients) {
+ RING_FOREACH_SAFE(link, next, &channel->clients) {
red_channel_client_pipe_add_empty_msg(
SPICE_CONTAINEROF(link, RedChannelClient, channel_link),
msg_type);
--
cgit v0.9.0.2-2-gbebe
|
