lib2302: fix crash due to stack overflow on MSVC and clang Windows

It fixes test 2302, 2303, 2307 with MSVC and clang on Windows.
GCC Windows builds were not affected.

Failure was caused by stack overflow due to a 1MB+ sized test struct on
stack. Replace it with dynamic allocation.

Also unignore affected tests in GHA/windows.

As seen under WINE with llvm-mingw:
```
$ wine64 libtests.exe lib2302 ws://127.0.0.1:59964/2302 > stdout2302 2> stderr2302
Test: lib2302
URL: ws://127.0.0.1:59964/2302
wine: Unhandled stack overflow at address 000000014007486A (thread 0024), starting debugger...
Unhandled exception: stack overflow in 64-bit code (0x000000014007486a).
```

Ref: #16629 (discovery)
Ref: 1bd5ac998bbc943dbf812b2824ad0f532201734c #16570

Closes #16630

diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index a3aeb6bd6843e7bf12ecf7f446043de87573479b..83c61d37b4bac6e7a3b760947cb95aa507e9acfb 100644 (file)
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -350,9 +350,6 @@ jobs:
           if [ '${{ matrix.sys }}' != 'msys' ]; then
             TFLAGS+=' ~612'  # SFTP
           fi
-          if [ '${{ matrix.sys }}' = 'clang64' ]; then
-            TFLAGS+=' ~2302 ~2303 ~2307'  # permafail with clang (and also MSVC) (but works with mingw64 and ucrt64)
-          fi
           if [ -x "$(cygpath "${SYSTEMROOT}/System32/curl.exe")" ]; then
             TFLAGS+=" -ac $(cygpath "${SYSTEMROOT}/System32/curl.exe")"
           fi
@@ -923,7 +920,7 @@ jobs:
         timeout-minutes: 10
         run: |
           export CURL_DIRSUFFIX='${{ matrix.type }}'
-          export TFLAGS='-j8 ${{ matrix.tflags }} ~2302 ~2303 ~2307'
+          export TFLAGS='-j8 ${{ matrix.tflags }}'
           TFLAGS+=' ~2310'  # flaky
           PATH="$PWD/bld/lib/${{ matrix.type }}:$PATH:/c/Program Files (x86)/stunnel/bin:/c/Program Files/OpenSSH-Win64"
           PATH="/c/msys64/usr/bin:$PATH"

diff --git a/tests/libtest/lib2302.c b/tests/libtest/lib2302.c
index 415ab9ff1f134019f3209204740e25878313b468..ccf8dfb5878a9af7718fb09939c2eedaf8228490 100644 (file)
--- a/tests/libtest/lib2302.c
+++ b/tests/libtest/lib2302.c
@@ -28,13 +28,15 @@
 
 struct ws_data {
   CURL *easy;
-  char buf[1024*1024];
+  char *buf;
   size_t blen;
   size_t nwrites;
   int has_meta;
   int meta_flags;
 };
 
+#define LIB2302_BUFSIZE (1024 * 1024)
+
 static void flush_data(struct ws_data *wd)
 {
   size_t i;
@@ -66,7 +68,7 @@ static size_t add_data(struct ws_data *wd, const char *buf, size_t blen,
     wd->meta_flags = meta ? meta->flags : 0;
   }
 
-  if(wd->blen + blen > sizeof(wd->buf)) {
+  if(wd->blen + blen > LIB2302_BUFSIZE) {
     return 0;
   }
   memcpy(wd->buf + wd->blen, buf, blen);
@@ -96,13 +98,16 @@ CURLcode test(char *URL)
   CURL *curl;
   CURLcode res = CURLE_OK;
   struct ws_data ws_data;
+  memset(&ws_data, 0, sizeof(ws_data));
 
+  ws_data.buf = (char *)calloc(LIB2302_BUFSIZE, 1);
+  if(!ws_data.buf)
+    return res;
 
   global_init(CURL_GLOBAL_ALL);
 
   curl = curl_easy_init();
   if(curl) {
-    memset(&ws_data, 0, sizeof(ws_data));
     ws_data.easy = curl;
 
     curl_easy_setopt(curl, CURLOPT_URL, URL);
@@ -118,6 +123,7 @@ CURLcode test(char *URL)
     flush_data(&ws_data);
   }
   curl_global_cleanup();
+  free(ws_data.buf);
   return res;
 }