Raise an error for an invalid number of bands in FPX image

python-pillow · Jan 2, 2020 · 774e53b · 774e53b
1 parent 8892aec
commit 774e53b
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Showing 3 changed files with 10 additions and 1 deletion.
diff --git a/Tests/images/input_bw_five_bands.fpx b/Tests/images/input_bw_five_bands.fpx
diff --git a/Tests/test_file_fpx.py b/Tests/test_file_fpx.py
@@ -1,3 +1,5 @@
+from PIL import Image
+
 from .helper import PillowTestCase, unittest
 
 try:
@@ -18,3 +20,7 @@ def test_invalid_file(self):
         # Test a valid OLE file, but not an FPX file
         ole_file = "Tests/images/test-ole-file.doc"
         self.assertRaises(SyntaxError, FpxImagePlugin.FpxImageFile, ole_file)
+
+    def test_fpx_invalid_number_of_bands(self):
+        with self.assertRaisesRegex(IOError, "Invalid number of bands"):
+            Image.open("Tests/images/input_bw_five_bands.fpx")
diff --git a/src/PIL/FpxImagePlugin.py b/src/PIL/FpxImagePlugin.py
@@ -104,7 +104,10 @@ def _open_index(self, index=1):
         s = prop[0x2000002 | id]
 
         colors = []
-        for i in range(i32(s, 4)):
+        bands = i32(s, 4)
+        if bands > 4:
+            raise IOError("Invalid number of bands")
+        for i in range(bands):
             # note: for now, we ignore the "uncalibrated" flag
             colors.append(i32(s, 8 + i * 4) & 0x7FFFFFFF)