commit 2f9fec72098278dc8b48f8626a2f0cc1d378be85
author Martin Storsjö <martin@martin.st> Mon Oct 28 23:46:34 2019 +0200
committer Copybara-Service <copybara-worker@google.com> Tue Nov 03 07:20:30 2020 -0800
tree a1c916db8e050230f327d296cb30754437555d6b
parent 6d60bfbcfc95f836a205117dc094343d878ecd83

[libcxx] Error out if __libcpp_mbsrtowcs_l fails in __time_get_storage

If __libcpp_mbsrtowcs_l outputs zero wchar_t's for week days or
month names (due to errors in the locale function setup), these are
matched all the time in __time_get_storage::__analyze, ending up in
an infinite loop, allocating more memory until killed.

Differential Revision: https://reviews.llvm.org/D69553

GitOrigin-RevId: 1127ef789c02e735357c9c9f2ffaf6291dc8e6d7

src/locale.cpp

diff --git a/src/locale.cpp b/src/locale.cpp
index 02dbb33..5fdc149 100644
--- a/src/locale.cpp
+++ b/src/locale.cpp
@@ -5128,7 +5128,7 @@
         mb = mbstate_t();
         const char* bb = buf;
         size_t j = __libcpp_mbsrtowcs_l(wbuf, &bb, countof(wbuf), &mb, __loc_);
-        if (j == size_t(-1))
+        if (j == size_t(-1) || j == 0)
             __throw_runtime_error("locale not supported");
         wbe = wbuf + j;
         __weeks_[i].assign(wbuf, wbe);
@@ -5136,7 +5136,7 @@
         mb = mbstate_t();
         bb = buf;
         j = __libcpp_mbsrtowcs_l(wbuf, &bb, countof(wbuf), &mb, __loc_);
-        if (j == size_t(-1))
+        if (j == size_t(-1) || j == 0)
             __throw_runtime_error("locale not supported");
         wbe = wbuf + j;
         __weeks_[i+7].assign(wbuf, wbe);
@@ -5149,7 +5149,7 @@
         mb = mbstate_t();
         const char* bb = buf;
         size_t j = __libcpp_mbsrtowcs_l(wbuf, &bb, countof(wbuf), &mb, __loc_);
-        if (j == size_t(-1))
+        if (j == size_t(-1) || j == 0)
             __throw_runtime_error("locale not supported");
         wbe = wbuf + j;
         __months_[i].assign(wbuf, wbe);
@@ -5157,7 +5157,7 @@
         mb = mbstate_t();
         bb = buf;
         j = __libcpp_mbsrtowcs_l(wbuf, &bb, countof(wbuf), &mb, __loc_);
-        if (j == size_t(-1))
+        if (j == size_t(-1) || j == 0)
             __throw_runtime_error("locale not supported");
         wbe = wbuf + j;
         __months_[i+12].assign(wbuf, wbe);