diff --git a/lib/connect.c b/lib/connect.c
index 271ce2b..4d4ea0e 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -231,23 +231,23 @@ void iscsi_defer_reconnect(struct iscsi_context *iscsi)
 
 int iscsi_reconnect(struct iscsi_context *old_iscsi)
 {
-	struct iscsi_context *iscsi = old_iscsi;
+	struct iscsi_context *iscsi;
 	int retry = 0;
 
 	/* if there is already a deferred reconnect do not try again */
-	if (iscsi->reconnect_deferred) {
-		ISCSI_LOG(iscsi, 2, "reconnect initiated, but reconnect is already deferred");
+	if (old_iscsi->reconnect_deferred) {
+		ISCSI_LOG(old_iscsi, 2, "reconnect initiated, but reconnect is already deferred");
 		return -1;
 	}
 
-	ISCSI_LOG(iscsi, 2, "reconnect initiated");
+	ISCSI_LOG(old_iscsi, 2, "reconnect initiated");
 
 	/* This is mainly for tests, where we do not want to automatically
 	   reconnect but rather want the commands to fail with an error
 	   if the target drops the session.
 	 */
-	if (iscsi->no_auto_reconnect) {
-		iscsi_defer_reconnect(iscsi);
+	if (old_iscsi->no_auto_reconnect) {
+		iscsi_defer_reconnect(old_iscsi);
 		return 0;
 	}
 
@@ -258,6 +258,11 @@ int iscsi_reconnect(struct iscsi_context *old_iscsi)
 try_again:
 
 	iscsi = iscsi_create_context(old_iscsi->initiator_name);
+	if (!iscsi) {
+		ISCSI_LOG(old_iscsi, 2, "failed to create new context for reconnection");
+		return -1;
+	}
+
 	iscsi->is_reconnecting = 1;
 
 	iscsi_set_targetname(iscsi, old_iscsi->target_name);
@@ -302,7 +307,7 @@ try_again:
 		if (backoff > 30) {
 			backoff = 30;
 		}
-		ISCSI_LOG(iscsi, 1, "reconnect try %d failed, waiting %d seconds", retry, backoff);
+		ISCSI_LOG(old_iscsi, 1, "reconnect try %d failed, waiting %d seconds", retry, backoff);
 		iscsi_destroy_context(iscsi);
 		sleep(backoff);
 		retry++;
@@ -370,11 +375,11 @@ try_again:
 	iscsi->mallocs+=old_iscsi->mallocs;
 	iscsi->frees+=old_iscsi->frees;
 
-	ISCSI_LOG(iscsi, 2, "reconnect was successful");
-
 	memcpy(old_iscsi, iscsi, sizeof(struct iscsi_context));
 	free(iscsi);
 
+	ISCSI_LOG(old_iscsi, 2, "reconnect was successful");
+
 	old_iscsi->is_reconnecting = 0;
 	old_iscsi->last_reconnect = time(NULL);
 
diff --git a/lib/discovery.c b/lib/discovery.c
index 52b7762..8301bea 100644
--- a/lib/discovery.c
+++ b/lib/discovery.c
@@ -118,25 +118,34 @@ iscsi_process_text_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 			      pdu->private_data);
 		return -1;
 	}
+	if (size == 0) {
+		iscsi_set_error(iscsi, "size == 0 when parsing "
+				"discovery data");
+		pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL,
+			      pdu->private_data);
+		return -1;
+	}
 
-	while (size > 0) {
+	do {
+		unsigned char *end;
 		int len;
 
-		len = strlen((char *)ptr);
-
-		if (len == 0) {
-			break;
-		}
-
-		if (len > size) {
-			iscsi_set_error(iscsi, "len > size when parsing "
-					"discovery data %d>%d", len, size);
+		end = memchr(ptr, 0, size);
+		if (end == NULL) {
+			iscsi_set_error(iscsi, "NUL not found after offset %ld "
+					"when parsing discovery data",
+					ptr - in->data);
 			pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL,
 				      pdu->private_data);
 			iscsi_free_discovery_addresses(iscsi, targets);
 			return -1;
 		}
 
+		len = end - ptr;
+		if (len == 0) {
+			break;
+		}
+
 		/* parse the strings */
 		if (!strncmp((char *)ptr, "TargetName=", 11)) {
 			struct iscsi_discovery_address *target;
@@ -166,6 +175,14 @@ iscsi_process_text_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 			target->next = targets;
 			targets = target;
 		} else if (!strncmp((char *)ptr, "TargetAddress=", 14)) {
+			if (targets == NULL || targets->target_address != NULL) {
+				iscsi_set_error(iscsi, "Invalid discovery "
+						"reply");
+				pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL,
+					      pdu->private_data);
+				iscsi_free_discovery_addresses(iscsi, targets);
+				return -1;
+			}
 			targets->target_address = iscsi_strdup(iscsi, (char *)ptr+14);
 			if (targets->target_address == NULL) {
 				iscsi_set_error(iscsi, "Failed to allocate "
@@ -187,7 +204,7 @@ iscsi_process_text_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 
 		ptr  += len + 1;
 		size -= len + 1;
-	}
+	} while (size > 0);
 
 	pdu->callback(iscsi, SCSI_STATUS_GOOD, targets, pdu->private_data);
 	iscsi_free_discovery_addresses(iscsi, targets);
diff --git a/lib/iscsi-command.c b/lib/iscsi-command.c
index 90d3fdb..f86ccaa 100644
--- a/lib/iscsi-command.c
+++ b/lib/iscsi-command.c
@@ -422,6 +422,7 @@ iscsi_process_scsi_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 		if (task->datain.data == NULL) {
 			iscsi_set_error(iscsi, "failed to allocate blob for "
 					"sense data");
+			break;
 		}
 		memcpy(task->datain.data, in->data, task->datain.size);
 
diff --git a/lib/login.c b/lib/login.c
index d3bce65..9a7347f 100644
--- a/lib/login.c
+++ b/lib/login.c
@@ -780,7 +780,7 @@ iscsi_login_async(struct iscsi_context *iscsi, iscsi_command_cb cb,
 	}
 
 	/* optional alias */
-	if (iscsi->alias) {
+	if (iscsi->alias[0]) {
 		if (iscsi_login_add_alias(iscsi, pdu) != 0) {
 			iscsi_free_pdu(iscsi, pdu);
 			return -1;
@@ -981,30 +981,40 @@ iscsi_process_login_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 	if (iscsi_serial32_compare(expcmdsn, iscsi->expcmdsn) > 0) {
 		iscsi->expcmdsn = expcmdsn;
 	}
-	
+
+	if (size == 0) {
+	       iscsi_set_error(iscsi, "size == 0 when parsing "
+			       "login data");
+	       pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL,
+			     pdu->private_data);
+	       return -1;
+	}
+
 	/* XXX here we should parse the data returned in case the target
 	 * renegotiated some some parameters.
 	 *  we should also do proper handshaking if the target is not yet
 	 * prepared to transition to the next stage
 	 */
 
-	while (size > 0) {
+	do {
+		char *end;
 		int len;
 
-		len = strlen(ptr);
-
-		if (len == 0) {
-			break;
-		}
-
-		if (len > size) {
-			iscsi_set_error(iscsi, "len > size when parsing "
-					"login data %d>%d", len, size);
+		end = memchr(ptr, 0, size);
+		if (end == NULL) {
+			iscsi_set_error(iscsi, "NUL not found after offset %ld "
+					"when parsing login data",
+					(unsigned char *)ptr - in->data);
 			pdu->callback(iscsi, SCSI_STATUS_ERROR, NULL,
 				      pdu->private_data);
 			return -1;
 		}
 
+		len = end - ptr;
+		if (len == 0) {
+			break;
+		}
+
 		/* parse the strings */
 		if (!strncmp(ptr, "TargetAddress=", 14)) {
 			strncpy(iscsi->target_address,ptr+14,MAX_STRING_SIZE);
@@ -1077,9 +1087,9 @@ iscsi_process_login_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 
 		ptr  += len + 1;
 		size -= len + 1;
-	}
+	} while (size > 0);
 
-	if (status == SCSI_STATUS_REDIRECT && iscsi->target_address) {
+	if (status == SCSI_STATUS_REDIRECT && iscsi->target_address[0]) {
 		ISCSI_LOG(iscsi, 2, "target requests redirect to %s",iscsi->target_address);
 		pdu->callback(iscsi, SCSI_STATUS_REDIRECT, NULL,
 				  pdu->private_data);
diff --git a/lib/socket.c b/lib/socket.c
index da8ff9d..1d40584 100644
--- a/lib/socket.c
+++ b/lib/socket.c
@@ -721,6 +721,9 @@ iscsi_service_reconnect_if_loggedin(struct iscsi_context *iscsi)
 int
 iscsi_service(struct iscsi_context *iscsi, int revents)
 {
+	if (iscsi->fd < 0)
+		return 0;
+
 	if (revents & POLLERR) {
 		int err = 0;
 		socklen_t err_size = sizeof(err);
@@ -755,7 +758,7 @@ iscsi_service(struct iscsi_context *iscsi, int revents)
 		return iscsi_service_reconnect_if_loggedin(iscsi);
 	}
 
-	if (iscsi->is_connected == 0 && iscsi->fd != -1 && revents&POLLOUT) {
+	if (iscsi->is_connected == 0 && revents&POLLOUT) {
 		int err = 0;
 		socklen_t err_size = sizeof(err);
 		struct sockaddr_in local;
diff --git a/src/iscsi-inq.c b/src/iscsi-inq.c
index 56e4903..ebc6e62 100644
--- a/src/iscsi-inq.c
+++ b/src/iscsi-inq.c
@@ -326,7 +326,7 @@ int main(int argc, char *argv[])
 	iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL);
 	iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
 
-	if (iscsi_url->user != NULL) {
+	if (iscsi_url->user[0]) {
 		if (iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user, iscsi_url->passwd) != 0) {
 			fprintf(stderr, "Failed to set initiator username and password\n");
 			exit(10);
diff --git a/src/iscsi-ls.c b/src/iscsi-ls.c
index eb0912c..a7f9013 100644
--- a/src/iscsi-ls.c
+++ b/src/iscsi-ls.c
@@ -425,7 +425,7 @@ int main(int argc, char *argv[])
 
 	iscsi_set_session_type(iscsi, ISCSI_SESSION_DISCOVERY);
 
-	if (iscsi_url->user != NULL) {
+	if (iscsi_url->user[0]) {
 		state.username = iscsi_url->user;
 		state.password = iscsi_url->passwd;
 		if (iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user, iscsi_url->passwd) != 0) {
diff --git a/src/iscsi-readcapacity16.c b/src/iscsi-readcapacity16.c
index 8749088..7a2adf7 100644
--- a/src/iscsi-readcapacity16.c
+++ b/src/iscsi-readcapacity16.c
@@ -149,7 +149,7 @@ int main(int argc, char *argv[])
 	iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL);
 	iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
 
-	if (iscsi_url->user != NULL) {
+	if (iscsi_url->user[0]) {
 		if (iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user, iscsi_url->passwd) != 0) {
 			fprintf(stderr, "Failed to set initiator username and password\n");
 			exit(10);