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authorPhilipp Gesang <phg@phi-gamma.net>2015-06-18 22:55:53 +0200
committerPhilipp Gesang <phg@phi-gamma.net>2015-06-18 22:55:53 +0200
commit7c2e8d69c755e05044a214dcefca164fd62d4727 (patch)
tree5fcd6e1f833576243ff9df15e8f5853883d55c65
parent54d4d86d58c301785b9d5859faadd2ad11537bc2 (diff)
downloadluaotfload-7c2e8d69c755e05044a214dcefca164fd62d4727.tar.gz
[parsers] set hard limit on fontconfig scanner recursion depth
-rw-r--r--src/luaotfload-parsers.lua41
1 files changed, 30 insertions, 11 deletions
diff --git a/src/luaotfload-parsers.lua b/src/luaotfload-parsers.lua
index a39d2cd..2ef32c3 100644
--- a/src/luaotfload-parsers.lua
+++ b/src/luaotfload-parsers.lua
@@ -17,9 +17,11 @@ if not modules then modules = { } end modules ['luaotfload-parsers'] = {
license = "GNU GPL v2.0"
}
-luaotfload = luaotfload or { }
-luaotfload.parsers = luaotfload.parsers or { }
-local parsers = luaotfload.parsers
+luaotfload = luaotfload or { }
+luaotfload.parsers = luaotfload.parsers or { }
+local parsers = luaotfload.parsers
+parsers.traversal_maxdepth = 42 --- prevent stack overflows
+local traversal_maxdepth = parsers.traversal_maxdepth --- TODO could be an option
local rawset = rawset
@@ -226,8 +228,9 @@ end
read_fonts_conf_indeed() -- Scan paths included from fontconfig
configuration files recursively. Called with eight arguments.
- The first four are
+ The first five are
+ · the current recursion depth
· the path to the file
· the expanded $HOME
· the expanded $XDG_CONFIG_HOME
@@ -240,12 +243,13 @@ end
--doc]]--
---- string -> string -> string -> string
+--- size_t -> string -> string -> string -> string
--- -> string list -> string list -> string list
--- -> (string -> fun option -> string list)
--- -> tab * tab * tab
local read_fonts_conf_indeed
-read_fonts_conf_indeed = function (start,
+read_fonts_conf_indeed = function (depth,
+ start,
home,
xdg_config_home,
xdg_data_home,
@@ -254,6 +258,18 @@ read_fonts_conf_indeed = function (start,
dirs_done,
find_files)
+ logreport ("both", 4, "db",
+ "Fontconfig scanner processing path %s.",
+ start)
+ if depth >= traversal_maxdepth then
+ --- prevent overflow of Lua call stack
+ logreport ("both", 0, "db",
+ "Fontconfig scanner hit recursion limit (%d); "
+ .. "aborting directory traversal.",
+ traversal_maxdepth)
+ return acc, done, dirs_done
+ end
+
local paths = fonts_conf_scanner(start)
if not paths then --- nothing to do
return acc, done, dirs_done
@@ -301,10 +317,11 @@ read_fonts_conf_indeed = function (start,
then
if done[path] then
logreport("log", 3, "load",
- "skipping file at %s, already included.", opt)
+ "Skipping file at %s, already included.", opt)
else
done[path] = true
- acc = read_fonts_conf_indeed(path,
+ acc = read_fonts_conf_indeed(depth + 1,
+ path,
home,
xdg_config_home,
xdg_data_home,
@@ -317,7 +334,8 @@ read_fonts_conf_indeed = function (start,
local config_files = find_files (path, conf_filter)
for _, filename in next, config_files do
if not done[filename] then
- acc = read_fonts_conf_indeed(filename,
+ acc = read_fonts_conf_indeed(depth + 1,
+ filename,
home,
xdg_config_home,
xdg_data_home,
@@ -328,7 +346,7 @@ read_fonts_conf_indeed = function (start,
end
end
end --- match “kind”
- end --- iterate paths
+ end --- iterate paths
end
--inspect(acc)
@@ -359,7 +377,8 @@ local read_fonts_conf = function (path_list, find_files)
local done = { } ---> set: files inspected
local dirs_done = { } ---> set: dirs in list
for i=1, #path_list do --- we keep the state between files
- acc, done, dirs_done = read_fonts_conf_indeed(path_list[i],
+ acc, done, dirs_done = read_fonts_conf_indeed(0,
+ path_list[i],
home,
xdg_config_home,
xdg_data_home,