Merge pull request #70 from dloebl/fix-32-bit-crash

Fix a potential crash on 32-bit systems
dloebl · Jun 18, 2024 · 6945c56 · 6945c56
2 parents 43976ce + 9cf32f3
commit 6945c56
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Showing 5 changed files with 91 additions and 8 deletions.
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -4,19 +4,34 @@ on:
   - pull_request
 jobs:
   build:
+    name: ${{ matrix.name }}
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os:
-          - ubuntu-22.04
-          - macos-12
-          - windows-2022
+        include:
+          - name: "Linux x64 (Ubuntu 22.04)"
+            os: ubuntu-22.04
+            config: {}
+          - name: "Linux 32-bit (Ubuntu 22.04)"
+            os: ubuntu-22.04
+            config: { cflags: "-m32"}
+          - name: "macOS 12"
+            os: macos-12
+            config: {}
+          - name: "Windows 2022"
+            os: windows-2022
+            config: {}
+    env:
+      CFLAGS: ${{ matrix.config.cflags }}
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
       - name: Dependencies (ubuntu)
         if: contains(matrix.os, 'ubuntu')
         run: sudo apt update && sudo apt install -y gifsicle valgrind meson
+      - name: Dependencies (ubuntu 32-bit)
+        if: contains(matrix.name, '32-bit')
+        run: sudo apt update && sudo apt install -y gcc-multilib
       - name: Dependencies (macos)
         if: contains(matrix.os, 'macos')
         run: brew install gifsicle meson
@@ -33,9 +48,9 @@ jobs:
         run: for f in build/*.gif; do gifsicle --no-ignore-errors --info $f || exit 1; done
         shell: bash
       - name: Valgrind
-        if: contains(matrix.os, 'ubuntu')
+        if: contains(matrix.name, 'Linux x64')
         run: meson test -C build --list | grep -v zip | grep -v checksums | sed 's/^/"/;s/$/"/' | xargs meson test -C build/ --wrap "valgrind --memcheck:leak-check=full --memcheck:show-leak-kinds=definite --memcheck:error-exitcode=1"
         shell: bash
       - name: Valgrind output
-        if: contains(matrix.os, 'ubuntu')
+        if: contains(matrix.name, 'Linux x64')
         run: cat build/meson-logs/testlog-valgrind.txt
diff --git a/src/cgif_raw.c b/src/cgif_raw.c
@@ -323,8 +323,8 @@ static int LZW_GenerateStream(LZWResult* pResult, const uint32_t numPixel, const
   // pack the generated LZW data into blocks of 255 bytes
   uint8_t *byteList; // lzw-data packed in byte-list
   uint8_t *byteListBlock; // lzw-data packed in byte-list with 255-block structure
-  uint64_t MaxByteListLen = MAX_CODE_LEN*lzwPos/8ul +2ul +1ul; // conservative upper bound
-  uint64_t MaxByteListBlockLen = MAX_CODE_LEN*lzwPos*(BLOCK_SIZE+1ul)/8ul/BLOCK_SIZE +2ul +1ul +1ul; // conservative upper bound
+  uint64_t MaxByteListLen = MAX_CODE_LEN * lzwPos / 8ull + 2ull + 1ull; // conservative upper bound
+  uint64_t MaxByteListBlockLen = MAX_CODE_LEN * lzwPos * (BLOCK_SIZE + 1ull) / 8ull / BLOCK_SIZE + 2ull + 1ull +1ull; // conservative upper bound
   byteList      = malloc(MaxByteListLen); // TBD check return value of malloc
   byteListBlock = malloc(MaxByteListBlockLen); // TBD check return value of malloc
   bytePos       = create_byte_list(byteList,lzwPos, pContext->pLZWData, initDictLen, initCodeLen);

diff --git a/tests/meson.build b/tests/meson.build
@@ -30,6 +30,7 @@ tests = [
   { 'name' : 'min_size',                           'seed_should_fail' : false},
   { 'name' : 'more_than_256_colors',               'seed_should_fail' : false},
   { 'name' : 'noise256',                           'seed_should_fail' : false},
+  { 'name' : 'noise256_large',                     'seed_should_fail' : false},
   { 'name' : 'noise6',                             'seed_should_fail' : false},
   { 'name' : 'noise6_interlaced',                  'seed_should_fail' : false},
   { 'name' : 'noloop',                             'seed_should_fail' : false},

diff --git a/tests/noise256_large.c b/tests/noise256_large.c
@@ -0,0 +1,66 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "cgif.h"
+
+#define WIDTH  3000
+#define HEIGHT 3000
+
+static uint64_t seed;
+
+// unsigned integer overflow expected
+__attribute__((no_sanitize("integer")))
+int psdrand(void) {
+  // simple pseudo random function from musl libc
+  seed = 6364136223846793005ULL * seed + 1;
+  return seed >> 33;
+}
+
+int main(void) {
+  CGIF*          pGIF;
+  CGIF_Config     gConfig;
+  CGIF_FrameConfig   fConfig;
+  uint8_t*      pImageData;
+  cgif_result   r;
+  uint8_t       aPalette[256 * 3];
+
+  seed = 22;
+  for(int i = 0; i < 256; ++i) {
+    aPalette[i * 3]     = psdrand() % 256;
+    aPalette[i * 3 + 1] = psdrand() % 256;
+    aPalette[i * 3 + 2] = psdrand() % 256;
+  }
+  memset(&gConfig, 0, sizeof(CGIF_Config));
+  memset(&fConfig, 0, sizeof(CGIF_FrameConfig));
+  gConfig.width                   = WIDTH;
+  gConfig.height                  = HEIGHT;
+  gConfig.pGlobalPalette          = aPalette;
+  gConfig.numGlobalPaletteEntries = 256;
+  gConfig.path                    = "noise256_large.gif";
+  //
+  // create new GIF
+  pGIF = cgif_newgif(&gConfig);
+  if(pGIF == NULL) {
+    fputs("failed to create new GIF via cgif_newgif()\n", stderr);
+    return 1;
+  }
+  //
+  // add frames to GIF
+  pImageData = malloc(WIDTH * HEIGHT);
+  for(int i = 0; i < WIDTH * HEIGHT; ++i) pImageData[i] = psdrand() % 256;
+  fConfig.pImageData = pImageData;
+  r = cgif_addframe(pGIF, &fConfig);
+  free(pImageData);
+  //
+  // write GIF to file
+  r = cgif_close(pGIF); // free allocated space at the end of the session
+
+  // check for errors
+  if(r != CGIF_OK) {
+    fprintf(stderr, "failed to create GIF. error code: %d\n", r);
+    return 2;
+  }
+  return 0;
+}
diff --git a/tests/tests.sha256 b/tests/tests.sha256
@@ -21,6 +21,7 @@ eeb9acd181da401748c9f39c59dbb5ecd71fd6f8f1685002f767de2ec0329bf4  min_color_tabl
 b263ce6bde416426b6676c320846f73870d40b2125bfc9630087c3c54df21ac8  min_size.gif
 5244e4ca77ea3923d27e790b9dddb6032a686e0272ba3d78ff5fa4af0523647b  more_than_256_colors.gif
 11c8de343ccd528e319afbe3ec0d0c657c1e6292faf6cb318713bcaf2979ab0d  noise256.gif
+75a2a7b04a21b785977fb2506e6468478418703835876755e78453223820b924  noise256_large.gif
 ff1da19b0448af07d8561f0ee62b184f99ac7dcb75f1a2215474190ec6648901  noise6.gif
 14cd8b2486e725d4136e1af656aa2398a882694fd1774ebfb23c57dae5ae00da  noise6_interlaced.gif
 98ec5ef9223f2c51bc2f4f94da4468f3b1e3c537a64d8050649787aaf433d13d  noloop.gif