* Avoid DoS while sending a message with a lot of recipients in 'To' header.

Fix possible deadlock in lua_redis.
Version is now 0.4.8 as there are enough changes.

3 files changed, 44 insertions, 5 deletions

diff --git a/src/lua/lua_redis.c b/src/lua/lua_redis.c
index 0358a6960..0c1934345 100644
--- a/src/lua/lua_redis.c
+++ b/src/lua/lua_redis.c
@@ -98,8 +98,12 @@ static void
 lua_redis_push_error (const gchar *err, struct lua_redis_userdata *ud, gboolean connected)
 {
 	struct worker_task					**ptask;
+	gboolean							  need_unlock = FALSE;
 
-	g_mutex_lock (lua_mtx);
+	/* Avoid LOR here as mutex can be acquired before in lua_call */
+	if (g_mutex_trylock (lua_mtx)) {
+		need_unlock = TRUE;
+	}
 	/* Push error */
 	lua_rawgeti (ud->L, LUA_REGISTRYINDEX, ud->cbref);
 	ptask = lua_newuserdata (ud->L, sizeof (struct worker_task *));
@@ -113,7 +117,9 @@ lua_redis_push_error (const gchar *err, struct lua_redis_userdata *ud, gboolean
 	if (lua_pcall (ud->L, 3, 0, 0) != 0) {
 		msg_info ("call to callback failed: %s", lua_tostring (ud->L, -1));
 	}
-	g_mutex_unlock (lua_mtx);
+	if (need_unlock) {
+		g_mutex_unlock (lua_mtx);
+	}
 
 	if (connected) {
 		remove_normal_event (ud->task->s, lua_redis_fin, ud);
@@ -130,8 +136,11 @@ static void
 lua_redis_push_data (const redisReply *r, struct lua_redis_userdata *ud)
 {
 	struct worker_task					**ptask;
+	gboolean							  need_unlock = FALSE;
 
-	g_mutex_lock (lua_mtx);
+	if (g_mutex_trylock (lua_mtx)) {
+		need_unlock = TRUE;
+	}
 	/* Push error */
 	lua_rawgeti (ud->L, LUA_REGISTRYINDEX, ud->cbref);
 	ptask = lua_newuserdata (ud->L, sizeof (struct worker_task *));
@@ -161,7 +170,9 @@ lua_redis_push_data (const redisReply *r, struct lua_redis_userdata *ud)
 	if (lua_pcall (ud->L, 3, 0, 0) != 0) {
 		msg_info ("call to callback failed: %s", lua_tostring (ud->L, -1));
 	}
-	g_mutex_unlock (lua_mtx);
+	if (need_unlock) {
+		g_mutex_unlock (lua_mtx);
+	}
 
 	remove_normal_event (ud->task->s, lua_redis_fin, ud);
 }
diff --git a/src/lua/lua_task.c b/src/lua/lua_task.c
index 5695b6f42..e44b873c0 100644
--- a/src/lua/lua_task.c
+++ b/src/lua/lua_task.c
@@ -69,6 +69,7 @@ LUA_FUNCTION_DEF (task, get_helo);
 LUA_FUNCTION_DEF (task, get_images);
 LUA_FUNCTION_DEF (task, get_symbol);
 LUA_FUNCTION_DEF (task, get_date);
+LUA_FUNCTION_DEF (task, get_message_id);
 LUA_FUNCTION_DEF (task, get_timeval);
 LUA_FUNCTION_DEF (task, get_metric_score);
 LUA_FUNCTION_DEF (task, get_metric_action);
@@ -101,6 +102,7 @@ static const struct luaL_reg    tasklib_m[] = {
 	LUA_INTERFACE_DEF (task, get_images),
 	LUA_INTERFACE_DEF (task, get_symbol),
 	LUA_INTERFACE_DEF (task, get_date),
+	LUA_INTERFACE_DEF (task, get_message_id),
 	LUA_INTERFACE_DEF (task, get_timeval),
 	LUA_INTERFACE_DEF (task, get_metric_score),
 	LUA_INTERFACE_DEF (task, get_metric_action),
@@ -1194,6 +1196,21 @@ lua_task_get_date (lua_State *L)
 }
 
 static gint
+lua_task_get_message_id (lua_State *L)
+{
+	struct worker_task             *task = lua_check_task (L);
+
+	if (task != NULL && task->message_id != NULL) {
+		lua_pushstring (L, task->message_id);
+	}
+	else {
+		lua_pushnil (L);
+	}
+
+	return 1;
+}
+
+static gint
 lua_task_get_timeval (lua_State *L)
 {
 	struct worker_task             *task = lua_check_task (L);
diff --git a/src/plugins/lua/ratelimit.lua b/src/plugins/lua/ratelimit.lua
index 7b1ea3eff..39bac5534 100644
--- a/src/plugins/lua/ratelimit.lua
+++ b/src/plugins/lua/ratelimit.lua
@@ -21,6 +21,7 @@ local bounce_senders = {'postmaster', 'mailer-daemon', '', 'null', 'fetchmail-da
 -- Do not check ratelimits for these senders
 local whitelisted_rcpts = {'postmaster', 'mailer-daemon'}
 local whitelisted_ip = nil
+local max_rcpt = 5
 local upstreams = nil
 
 --- Parse atime and bucket of limit
@@ -167,6 +168,11 @@ local function rate_test_set(task, func)
 		rcpts = task:get_recipients_headers()
 	end
 	if rcpts then
+		if table.maxn(rcpts) > max_rcpt then
+			rspamd_logger.info(string.format('message <%s> contains %d recipients, maximum is %d',
+				task:get_message_id(), table.maxn(rcpts), max_rcpt))
+			return
+		end
 		for i,r in ipairs(rcpts) do
 			rcpts_user[i] = get_local_part(r['addr'])
 		end
@@ -276,6 +282,7 @@ if rspamd_config:get_api_version() >= 9 then
 	rspamd_config:register_module_option('ratelimit', 'whitelisted_rcpts', 'string')
 	rspamd_config:register_module_option('ratelimit', 'whitelisted_ip', 'map')
 	rspamd_config:register_module_option('ratelimit', 'limit', 'string')
+	rspamd_config:register_module_option('ratelimit', 'max_rcpt', 'uint')
 end
 
 local function parse_whitelisted_rcpts(str)
@@ -301,6 +308,10 @@ if opts then
 		whitelisted_ip = rspamd_config:add_hash_map (opts['whitelisted_ip'])
 	end
 	
+	if opts['max_rcpt'] then
+		max_rcpt = tonumber (opts['max_rcpt'])
+	end
+	
 	if not opts['servers'] then
 		rspamd_logger.err('no servers are specified')
 	else
@@ -312,4 +323,4 @@ if opts then
 			rspamd_config:register_post_filter(rate_set)
 		end
 	end
-end
+end
\ No newline at end of file