From 963d52f63ee838a51cf8ed2509b27415dd718bd0 Mon Sep 17 00:00:00 2001
From: Richard Mudgett <rmudgett@digium.com>
Date: Wed, 4 Jan 2012 20:55:59 +0000
Subject: [PATCH] Fix segfault in chan_dahdi for CHANNEL(dahdi_span) evaluation
 on hangup.

* Added NULL private pointer checks in the following chan_dahdi channel
callbacks: dahdi_func_read(), dahdi_func_write(), dahdi_setoption(), and
dahdi_queryoption().

(closes issue ASTERISK-19142)
Reported by: Diego Aguirre
Tested by: rmudgett
........

Merged revisions 349558 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 349559 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@349560 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 channels/chan_dahdi.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index f0ae82650e..ce5b28bf2d 100644
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -6655,7 +6655,7 @@ static int dahdi_queryoption(struct ast_channel *chan, int option, void *data, i
 	struct dahdi_pvt *p = chan->tech_pvt;
 
 	/* all supported options require data */
-	if (!data || (*datalen < 1)) {
+	if (!p || !data || (*datalen < 1)) {
 		errno = EINVAL;
 		return -1;
 	}
@@ -6701,7 +6701,7 @@ static int dahdi_setoption(struct ast_channel *chan, int option, void *data, int
 
 
 	/* all supported options require data */
-	if (!data || (datalen < 1)) {
+	if (!p || !data || (datalen < 1)) {
 		errno = EINVAL;
 		return -1;
 	}
@@ -6914,6 +6914,12 @@ static int dahdi_func_read(struct ast_channel *chan, const char *function, char
 	struct dahdi_pvt *p = chan->tech_pvt;
 	int res = 0;
 
+	if (!p) {
+		/* No private structure! */
+		*buf = '\0';
+		return -1;
+	}
+
 	if (!strcasecmp(data, "rxgain")) {
 		ast_mutex_lock(&p->lock);
 		snprintf(buf, len, "%f", p->rxgain);
@@ -7047,6 +7053,11 @@ static int dahdi_func_write(struct ast_channel *chan, const char *function, char
 	struct dahdi_pvt *p = chan->tech_pvt;
 	int res = 0;
 
+	if (!p) {
+		/* No private structure! */
+		return -1;
+	}
+
 	if (!strcasecmp(data, "buffers")) {
 		int num_bufs, policy;
 
-- 
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