channel: do not free rcc->stream in red_channel_client_disconnect

This fixes a crash if red_channel_client disconnect is called
handling a message.
This can happen for instance while handling SPICE_MSGC_ACK which calls
red_channel_client_push which tries to detect write errors while writing
to a socket (for instance socket disconnection).
Messages are read in a loop and red_channel_client_disconnect would
cause rcc->stream to be NULL which will result in a use-after-free
problem (stream in red_peer_handle_incoming will use cached stream value).

Signed-off-by: Marc-André Lureau <marcandre.lureau@gmail.com>
Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
Acked-by: Jonathon Jongsma <jjongsma@redhat.com>
This commit is contained in:
Frediano Ziglio 2016-01-19 10:35:48 +00:00
parent a5a0d4a290
commit ddaa46d70f

View File

@ -1233,6 +1233,10 @@ void red_channel_client_unref(RedChannelClient *rcc)
{
if (!--rcc->refs) {
spice_debug("destroy rcc=%p", rcc);
reds_stream_free(rcc->stream);
rcc->stream = NULL;
if (rcc->send_data.main.marshaller) {
spice_marshaller_destroy(rcc->send_data.main.marshaller);
}
@ -1749,7 +1753,7 @@ void red_channel_pipes_add_empty_msg(RedChannel *channel, int msg_type)
int red_channel_client_is_connected(RedChannelClient *rcc)
{
if (!rcc->dummy) {
return rcc->stream != NULL;
return ring_item_is_linked(&rcc->channel_link);
} else {
return rcc->dummy_connected;
}
@ -1804,6 +1808,8 @@ static void red_channel_remove_client(RedChannelClient *rcc)
rcc->channel->type, rcc->channel->id,
rcc->channel->thread_id, pthread_self());
}
spice_return_if_fail(ring_item_is_linked(&rcc->channel_link));
ring_remove(&rcc->channel_link);
spice_assert(rcc->channel->clients_num > 0);
rcc->channel->clients_num--;
@ -1845,8 +1851,6 @@ void red_channel_client_disconnect(RedChannelClient *rcc)
rcc->channel->core->watch_remove(rcc->stream->watch);
rcc->stream->watch = NULL;
}
reds_stream_free(rcc->stream);
rcc->stream = NULL;
if (rcc->latency_monitor.timer) {
rcc->channel->core->timer_remove(rcc->latency_monitor.timer);
rcc->latency_monitor.timer = NULL;