From 2045db6a6983efee2abb65863d50e7c67361df1d Mon Sep 17 00:00:00 2001
From: Richard Mudgett <rmudgett@digium.com>
Date: Thu, 14 Oct 2010 17:09:40 +0000
Subject: [PATCH] Segfault in pri_schedule_del() - ctrl value is invalid.

Validate the given call pointer in libpri API calls.  If the call pointer
is not an active call record then a complaint message is issued and the
API call aborts.  The call pointer is likely stale.

This patch is defensive.  More information is needed to figure out why
Asterisk still has a call pointer during its hangup sequence.

(closes issue #17522)
(closes issue #18032)
Reported by: schmoozecom
Patches:
      issue_18032_v1.4.patch uploaded by rmudgett (license 664)
Tested by: rmudgett


git-svn-id: https://origsvn.digium.com/svn/libpri/branches/1.4@2015 2fbb986a-6c06-0410-b554-c9c1f0a7f128
---
 pri.c          | 104 ++++++++++++++++++++++++++++++++++---------------
 pri_aoc.c      |  10 ++---
 pri_cc.c       |   4 +-
 pri_facility.c |   6 +--
 pri_internal.h |  14 +++++++
 q931.c         |  70 +++++++++++++++++++++++++++++++++
 6 files changed, 166 insertions(+), 42 deletions(-)

diff --git a/pri.c b/pri.c
index 97ca6dc..6cb0e0d 100644
--- a/pri.c
+++ b/pri.c
@@ -416,8 +416,15 @@ struct pri *__pri_new_tei(int fd, int node, int switchtype, struct pri *master,
 
 void pri_call_set_useruser(q931_call *c, const char *userchars)
 {
-	if (userchars)
-		libpri_copy_string(c->useruserinfo, userchars, sizeof(c->useruserinfo));
+	/*
+	 * There is a slight risk here if c is actually stale.  However,
+	 * if it is stale then it is better to catch it here than to
+	 * write with it.
+	 */
+	if (!userchars || !pri_is_call_valid(NULL, c)) {
+		return;
+	}
+	libpri_copy_string(c->useruserinfo, userchars, sizeof(c->useruserinfo));
 }
 
 void pri_sr_set_useruser(struct pri_sr *sr, const char *userchars)
@@ -642,80 +649,89 @@ void pri_facility_enable(struct pri *pri)
 
 int pri_acknowledge(struct pri *pri, q931_call *call, int channel, int info)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 	return q931_alerting(pri, call, channel, info);
 }
 
 int pri_proceeding(struct pri *pri, q931_call *call, int channel, int info)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 	return q931_call_proceeding(pri, call, channel, info);
 }
 
 int pri_progress_with_cause(struct pri *pri, q931_call *call, int channel, int info, int cause)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 
 	return q931_call_progress_with_cause(pri, call, channel, info, cause);
 }
 
 int pri_progress(struct pri *pri, q931_call *call, int channel, int info)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 
 	return q931_call_progress(pri, call, channel, info);
 }
 
 int pri_information(struct pri *pri, q931_call *call, char digit)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 	return q931_information(pri, call, digit);
 }
 
 int pri_keypad_facility(struct pri *pri, q931_call *call, const char *digits)
 {
-	if (!pri || !call || !digits || !digits[0])
+	if (!pri || !pri_is_call_valid(pri, call) || !digits || !digits[0]) {
 		return -1;
+	}
 
 	return q931_keypad_facility(pri, call, digits);
 }
 
 int pri_notify(struct pri *pri, q931_call *call, int channel, int info)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 	return q931_notify(pri, call, channel, info);
 }
 
 void pri_destroycall(struct pri *pri, q931_call *call)
 {
-	if (pri && call)
+	if (pri && pri_is_call_valid(pri, call)) {
 		q931_destroycall(pri, call);
-	return;
+	}
 }
 
 int pri_need_more_info(struct pri *pri, q931_call *call, int channel, int nonisdn)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 	return q931_setup_ack(pri, call, channel, nonisdn);
 }
 
 int pri_answer(struct pri *pri, q931_call *call, int channel, int nonisdn)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 	return q931_connect(pri, call, channel, nonisdn);
 }
 
 int pri_connect_ack(struct pri *ctrl, q931_call *call, int channel)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 	return q931_connect_acknowledge(ctrl, call, channel);
@@ -821,7 +837,7 @@ int pri_connected_line_update(struct pri *ctrl, q931_call *call, const struct pr
 	unsigned idx;
 	struct q931_call *subcall;
 
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 
@@ -887,7 +903,7 @@ int pri_redirecting_update(struct pri *ctrl, q931_call *call, const struct pri_p
 	unsigned idx;
 	struct q931_call *subcall;
 
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 
@@ -1037,15 +1053,17 @@ void pri_status_req_rsp(struct pri *ctrl, int invoke_id, int status)
 /* deprecated routines, use pri_hangup */
 int pri_release(struct pri *pri, q931_call *call, int cause)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 	return q931_release(pri, call, cause);
 }
 
 int pri_disconnect(struct pri *pri, q931_call *call, int cause)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 	return q931_disconnect(pri, call, cause);
 }
 #endif
@@ -1054,8 +1072,14 @@ int pri_channel_bridge(q931_call *call1, q931_call *call2)
 {
 	struct q931_call *winner;
 
-	if (!call1 || !call2)
+	/*
+	 * There is a slight risk here if call1 or call2 is actually
+	 * stale.  However, if they are stale then it is better to catch
+	 * it here than to write with these pointers.
+	 */
+	if (!pri_is_call_valid(NULL, call1) || !pri_is_call_valid(NULL, call2)) {
 		return -1;
+	}
 
 	winner = q931_find_winning_call(call1);
 	if (!winner) {
@@ -1122,8 +1146,9 @@ void pri_hangup_fix_enable(struct pri *ctrl, int enable)
 
 int pri_hangup(struct pri *pri, q931_call *call, int cause)
 {
-	if (!pri || !call)
+	if (!pri || !pri_is_call_valid(pri, call)) {
 		return -1;
+	}
 	if (cause == -1)
 		/* normal clear cause */
 		cause = PRI_CAUSE_NORMAL_CLEARING;
@@ -1201,8 +1226,10 @@ int pri_mwi_activate(struct pri *pri, q931_call *c, char *caller, int callerplan
 					int calledplan)
 {
 	struct pri_sr req;
-	if (!pri || !c)
+
+	if (!pri || !pri_is_call_valid(pri, c)) {
 		return -1;
+	}
 
 	pri_sr_init(&req);
 	pri_sr_set_connection_call_independent(&req);
@@ -1221,8 +1248,10 @@ int pri_mwi_deactivate(struct pri *pri, q931_call *c, char *caller, int callerpl
 					int calledplan)
 {
 	struct pri_sr req;
-	if (!pri || !c)
+
+	if (!pri || !pri_is_call_valid(pri, c)) {
 		return -1;
+	}
 
 	pri_sr_init(&req);
 	pri_sr_set_connection_call_independent(&req);
@@ -1239,8 +1268,9 @@ int pri_mwi_deactivate(struct pri *pri, q931_call *c, char *caller, int callerpl
 	
 int pri_setup(struct pri *pri, q931_call *c, struct pri_sr *req)
 {
-	if (!pri || !c)
+	if (!pri || !pri_is_call_valid(pri, c)) {
 		return -1;
+	}
 
 	return q931_setup(pri, c, req);
 }
@@ -1250,8 +1280,11 @@ int pri_call(struct pri *pri, q931_call *c, int transmode, int channel, int excl
 					int calledplan, int ulayer1)
 {
 	struct pri_sr req;
-	if (!pri || !c)
+
+	if (!pri || !pri_is_call_valid(pri, c)) {
 		return -1;
+	}
+
 	pri_sr_init(&req);
 	pri_sr_set_caller(&req, caller, callername, callerplan, callerpres);
 	pri_sr_set_called(&req, called, calledplan, 0);
@@ -1494,11 +1527,17 @@ char *pri_dump_info_str(struct pri *ctrl)
 
 int pri_get_crv(struct pri *pri, q931_call *call, int *callmode)
 {
+	if (!pri || !pri_is_call_valid(pri, call)) {
+		return -1;
+	}
 	return q931_call_getcrv(pri, call, callmode);
 }
 
 int pri_set_crv(struct pri *pri, q931_call *call, int crv, int callmode)
 {
+	if (!pri || !pri_is_call_valid(pri, call)) {
+		return -1;
+	}
 	return q931_call_setcrv(pri, call, crv, callmode);
 }
 
@@ -1655,7 +1694,7 @@ void pri_hold_enable(struct pri *ctrl, int enable)
 
 int pri_hold(struct pri *ctrl, q931_call *call)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 	return q931_send_hold(ctrl, call);
@@ -1663,7 +1702,7 @@ int pri_hold(struct pri *ctrl, q931_call *call)
 
 int pri_hold_ack(struct pri *ctrl, q931_call *call)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 	return q931_send_hold_ack(ctrl, call);
@@ -1671,7 +1710,7 @@ int pri_hold_ack(struct pri *ctrl, q931_call *call)
 
 int pri_hold_rej(struct pri *ctrl, q931_call *call, int cause)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 	return q931_send_hold_rej(ctrl, call, cause);
@@ -1679,7 +1718,7 @@ int pri_hold_rej(struct pri *ctrl, q931_call *call, int cause)
 
 int pri_retrieve(struct pri *ctrl, q931_call *call, int channel)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 	return q931_send_retrieve(ctrl, call, channel);
@@ -1687,7 +1726,7 @@ int pri_retrieve(struct pri *ctrl, q931_call *call, int channel)
 
 int pri_retrieve_ack(struct pri *ctrl, q931_call *call, int channel)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 	return q931_send_retrieve_ack(ctrl, call, channel);
@@ -1695,7 +1734,7 @@ int pri_retrieve_ack(struct pri *ctrl, q931_call *call, int channel)
 
 int pri_retrieve_rej(struct pri *ctrl, q931_call *call, int cause)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 	return q931_send_retrieve_rej(ctrl, call, cause);
@@ -1703,8 +1742,9 @@ int pri_retrieve_rej(struct pri *ctrl, q931_call *call, int cause)
 
 int pri_callrerouting_facility(struct pri *pri, q931_call *call, const char *dest, const char* original, const char* reason)
 {
-	if (!pri || !call || !dest)
+	if (!pri || !pri_is_call_valid(pri, call) || !dest) {
 		return -1;
+	}
 
 	return qsig_cf_callrerouting(pri, call, dest, original, reason);
 }
@@ -1723,7 +1763,7 @@ int pri_reroute_call(struct pri *ctrl, q931_call *call, const struct pri_party_i
 	struct q931_party_id local_caller;
 	struct q931_party_redirecting reroute;
 
-	if (!ctrl || !call || !deflection) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call) || !deflection) {
 		return -1;
 	}
 
diff --git a/pri_aoc.c b/pri_aoc.c
index 46993dd..23d7be6 100644
--- a/pri_aoc.c
+++ b/pri_aoc.c
@@ -1610,7 +1610,7 @@ static int aoc_e_encode(struct pri *ctrl, q931_call *call, const struct pri_subc
 
 int pri_aoc_de_request_response_send(struct pri *ctrl, q931_call *call, int response, int invoke_id)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 
@@ -1629,7 +1629,7 @@ int pri_aoc_de_request_response_send(struct pri *ctrl, q931_call *call, int resp
 
 int pri_aoc_s_request_response_send(struct pri *ctrl, q931_call *call, int invoke_id, const struct pri_subcmd_aoc_s *aoc_s)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 
@@ -1692,7 +1692,7 @@ int aoc_charging_request_send(struct pri *ctrl, q931_call *call, enum PRI_AOC_RE
 
 int pri_aoc_s_send(struct pri *ctrl, q931_call *call, const struct pri_subcmd_aoc_s *aoc_s)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 
@@ -1711,7 +1711,7 @@ int pri_aoc_s_send(struct pri *ctrl, q931_call *call, const struct pri_subcmd_ao
 
 int pri_aoc_d_send(struct pri *ctrl, q931_call *call, const struct pri_subcmd_aoc_d *aoc_d)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 
@@ -1729,7 +1729,7 @@ int pri_aoc_d_send(struct pri *ctrl, q931_call *call, const struct pri_subcmd_ao
 
 int pri_aoc_e_send(struct pri *ctrl, q931_call *call, const struct pri_subcmd_aoc_e *aoc_e)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 
diff --git a/pri_cc.c b/pri_cc.c
index 93089b0..407e24b 100644
--- a/pri_cc.c
+++ b/pri_cc.c
@@ -6803,7 +6803,7 @@ long pri_cc_available(struct pri *ctrl, q931_call *call)
 	struct pri_cc_record *cc_record;
 	long cc_id;
 
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 	if (call->cc.record) {
@@ -7811,7 +7811,7 @@ int pri_cc_call(struct pri *ctrl, long cc_id, q931_call *call, struct pri_sr *re
 {
 	struct pri_cc_record *cc_record;
 
-	if (!ctrl || !call || !req) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call) || !req) {
 		return -1;
 	}
 	cc_record = pri_cc_find_by_id(ctrl, cc_id);
diff --git a/pri_facility.c b/pri_facility.c
index 158e39e..ed01b45 100644
--- a/pri_facility.c
+++ b/pri_facility.c
@@ -3632,7 +3632,7 @@ int pri_rerouting_rsp(struct pri *ctrl, q931_call *call, int invoke_id, enum PRI
 {
 	enum rose_error_code rose_err;
 
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 
@@ -3673,7 +3673,7 @@ int pri_rerouting_rsp(struct pri *ctrl, q931_call *call, int invoke_id, enum PRI
 
 int pri_transfer_rsp(struct pri *ctrl, q931_call *call, int invoke_id, int is_successful)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 
@@ -3804,7 +3804,7 @@ static int rose_mcid_req_encode(struct pri *ctrl, q931_call *call)
 
 int pri_mcid_req_send(struct pri *ctrl, q931_call *call)
 {
-	if (!ctrl || !call) {
+	if (!ctrl || !pri_is_call_valid(ctrl, call)) {
 		return -1;
 	}
 	if (call->cc.originated) {
diff --git a/pri_internal.h b/pri_internal.h
index 3b8c379..84f5a27 100644
--- a/pri_internal.h
+++ b/pri_internal.h
@@ -882,6 +882,20 @@ struct d_ctrl_dummy {
 	struct q931_call dummy_call;
 };
 
+/*!
+ * \brief Check if the given call ptr is valid.
+ *
+ * \param ctrl D channel controller.
+ * \param call Q.931 call leg.
+ *
+ * \retval TRUE if call ptr is valid.
+ * \retval FALSE if call ptr is invalid.
+ */
+#define pri_is_call_valid(ctrl, call)	\
+	q931_is_call_valid(ctrl, call, __PRETTY_FUNCTION__, __LINE__)
+
+int q931_is_call_valid(struct pri *ctrl, struct q931_call *call, const char *func_name, unsigned long func_line);
+
 extern int pri_schedule_event(struct pri *pri, int ms, void (*function)(void *data), void *data);
 
 extern pri_event *pri_schedule_run(struct pri *pri);
diff --git a/q931.c b/q931.c
index 0d40f9b..c26453a 100644
--- a/q931.c
+++ b/q931.c
@@ -322,6 +322,76 @@ static int q931_encode_channel(const q931_call *call)
 		| held_call;
 }
 
+/*!
+ * \brief Check if the given call ptr is valid.
+ *
+ * \param ctrl D channel controller.
+ * \param call Q.931 call leg.
+ * \param func_name Calling function name for debug tracing. (__PRETTY_FUNCTION__)
+ * \param func_line Calling function line number for debug tracing. (__LINE__)
+ *
+ * \retval TRUE if call ptr is valid.
+ * \retval FALSE if call ptr is invalid.
+ */
+int q931_is_call_valid(struct pri *ctrl, struct q931_call *call, const char *func_name, unsigned long func_line)
+{
+	struct q931_call *cur;
+	struct pri *gripe;
+	struct pri *link;
+	int idx;
+
+	if (!call) {
+		return 0;
+	}
+
+	if (!ctrl) {
+		/* Must use suspect ctrl from call ptr. */
+		if (!call->pri) {
+			pri_message(NULL,
+				"!! %s() line:%lu Called with invalid call ptr (%p) (No ctrl)\n",
+				func_name, func_line, call);
+			return 0;
+		}
+		/* Find the master - He has the call pool */
+		ctrl = PRI_MASTER(call->pri);
+		gripe = NULL;
+	} else {
+		/* Find the master - He has the call pool */
+		ctrl = PRI_MASTER(ctrl);
+		gripe = ctrl;
+	}
+
+	/* Check real call records. */
+	for (cur = *ctrl->callpool; cur; cur = cur->next) {
+		if (call == cur) {
+			/* Found it. */
+			return 1;
+		}
+		if (cur->outboundbroadcast) {
+			/* Check subcalls for call ptr. */
+			for (idx = 0; idx < ARRAY_LEN(cur->subcalls); ++idx) {
+				if (call == cur->subcalls[idx]) {
+					/* Found it. */
+					return 1;
+				}
+			}
+		}
+	}
+
+	/* Check dummy call records. */
+	for (link = ctrl; link; link = link->subchannel) {
+		if (link->dummy_call == call) {
+			/* Found it. */
+			return 1;
+		}
+	}
+
+	/* Well it looks like this is a stale call ptr. */
+	pri_message(gripe, "!! %s() line:%lu Called with invalid call ptr (%p)\n",
+		func_name, func_line, call);
+	return 0;
+}
+
 /*!
  * \brief Initialize the given struct q931_party_name
  *