Merge "liblog: log reader validate headers" (0321476f) · Commits · e / os / android_system_core

liblog/logger_read.c

+51 −8

Original line number	Diff line number	Diff line
		@@ -341,6 +341,43 @@ LIBLOG_ABI_PUBLIC struct logger_list *android_logger_list_open(
		return logger_list;
		}

		/* Validate log_msg packet, read function has already been null checked */
		static int android_transport_read(struct android_log_logger_list *logger_list,
		struct android_log_transport_context *transp,
		struct log_msg *log_msg)
		{
		int ret = (*transp->transport->read)(logger_list, transp, log_msg);

		if (ret > (int)sizeof(*log_msg)) {
		ret = sizeof(*log_msg);
		}

		transp->ret = ret;

		/* propagate errors, or make sure len & hdr_size members visible */
		if (ret < (int)(sizeof(log_msg->entry.len) +
		sizeof(log_msg->entry.hdr_size))) {
		if (ret >= (int)sizeof(log_msg->entry.len)) {
		log_msg->entry.len = 0;
		}
		return ret;
		}

		/* hdr_size correction (logger_entry -> logger_entry_v2+ conversion) */
		if (log_msg->entry_v2.hdr_size == 0) {
		log_msg->entry_v2.hdr_size = sizeof(struct logger_entry);
		}

		/* len validation */
		if (ret <= log_msg->entry_v2.hdr_size) {
		log_msg->entry.len = 0;
		} else {
		log_msg->entry.len = ret - log_msg->entry_v2.hdr_size;
		}

		return ret;
		}

		/* Read from the selected logs */
		LIBLOG_ABI_PUBLIC int android_logger_list_read(struct logger_list *logger_list,
		struct log_msg *log_msg)
		@@ -378,7 +415,7 @@ LIBLOG_ABI_PUBLIC int android_logger_list_read(struct logger_list *logger_list,
		} else if ((logger_list_internal->mode &
		ANDROID_LOG_NONBLOCK) \|\|
		!transp->transport->poll) {
		retval = transp->ret = (*transp->transport->read)(
		retval = android_transport_read(
		logger_list_internal,
		transp,
		&transp->logMsg);
		@@ -397,7 +434,7 @@ LIBLOG_ABI_PUBLIC int android_logger_list_read(struct logger_list *logger_list,
		}
		retval = transp->ret = pollval;
		} else if (pollval > 0) {
		retval = transp->ret = (*transp->transport->read)(
		retval = android_transport_read(
		logger_list_internal,
		transp,
		&transp->logMsg);
		@@ -434,16 +471,22 @@ LIBLOG_ABI_PUBLIC int android_logger_list_read(struct logger_list *logger_list,
		if (!oldest) {
		return ret;
		}
		memcpy(log_msg, &oldest->logMsg, oldest->logMsg.entry.len +
		(oldest->logMsg.entry.hdr_size ?
		oldest->logMsg.entry.hdr_size :
		sizeof(struct logger_entry)));
		// ret is a positive value less than sizeof(struct log_msg)
		ret = oldest->ret;
		if (ret < oldest->logMsg.entry.hdr_size) {
		// zero truncated header fields.
		memset(log_msg, 0,
		(oldest->logMsg.entry.hdr_size > sizeof(oldest->logMsg) ?
		sizeof(oldest->logMsg) :
		oldest->logMsg.entry.hdr_size));
		}
		memcpy(log_msg, &oldest->logMsg, ret);
		oldest->logMsg.entry.len = 0; /* Mark it as copied */
		return oldest->ret;
		return ret;
		}

		/* if only one, no need to copy into transport_context and merge-sort */
		return (transp->transport->read)(logger_list_internal, transp, log_msg);
		return android_transport_read(logger_list_internal, transp, log_msg);
		}

		/* Close all the logs */