From 1efe727ed87df803d2ce7aa1f77242d103c43b1d Mon Sep 17 00:00:00 2001
From: Matthew Jordan <mjordan@digium.com>
Date: Thu, 14 Jun 2012 17:34:10 +0000
Subject: [PATCH] AST-2012-009: Fix crash in chan_skinny due to Key Pad Button
Message handling
AST-2012-008 (r367844) fixed a denial of service attack exploitable in the
Skinny channel driver that occurred when certain messages are sent after a
previously registered station sends an Off Hook message. Unresolved in that
patch is an issue in the Asterisk 10 releases, wherein, if a Station Key
Pad Button Message is processed after an Off Hook message, the channel driver
will inappropriately dereference a NULL pointer.
This patch fixes those places where the message handling or the channel
callback functions would attempt to dereference the line's pointer to the
device.
(issue ASTERISK-19905)
Reported by: Christoph Hebeisen
Tested by: mjordan, Christoph Hebeisen
Patches:
AST-2012-009-10.diff uploaded by mjordan (license 6283)
........
Merged revisions 368947 from http://svn.asterisk.org/svn/asterisk/branches/10
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@368948 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
channels/chan_skinny.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/channels/chan_skinny.c b/channels/chan_skinny.c
index 1c89674b9c..9322bf50a8 100644
--- a/channels/chan_skinny.c
+++ b/channels/chan_skinny.c
@@ -5011,6 +5011,11 @@ static void setsubstate(struct skinny_subchannel *sub, int state)
pthread_t t;
int actualstate = state;
+ if (!l->device) {
+ ast_log(LOG_WARNING, "Device for line %s is not registered.\n", l->name);
+ return;
+ }
+
if (sub->substate == SUBSTATE_ONHOOK) {
return;
}
@@ -5403,15 +5408,20 @@ static void dumpsub(struct skinny_subchannel *sub, int forcehangup)
struct skinny_subchannel *activate_sub = NULL;
struct skinny_subchannel *tsub;
+ if (!l->device) {
+ ast_log(LOG_WARNING, "Device for line %s is not registered.\n", l->name);
+ return;
+ }
+
if (skinnydebug) {
ast_verb(3, "Sub %d - Dumping\n", sub->callid);
}
-
+
if (!forcehangup && sub->substate == SUBSTATE_HOLD) {
l->activesub = NULL;
return;
}
-
+
if (sub == l->activesub) {
d->hookstate = SKINNY_ONHOOK;
transmit_speaker_mode(d, SKINNY_SPEAKEROFF);
--
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