From d4663806a89d28e30cbb9f7eac7b03a04f09cb31 Mon Sep 17 00:00:00 2001
From: wiredfool <eric-github@soroos.net>
Date: Sun, 25 Sep 2016 10:44:22 +0100
Subject: [PATCH] Memory error in Storage.c when accepting negative image size
 arguments

---
 Tests/images/negative_size.ppm | Bin 0 -> 19 bytes
 Tests/test_file_ppm.py         |  12 ++++++++++++
 libImaging/Storage.c           |   4 ++++
 3 files changed, 16 insertions(+)
 create mode 100755 Tests/images/negative_size.ppm

diff --git a/Tests/images/negative_size.ppm b/Tests/images/negative_size.ppm
new file mode 100755
index 0000000000000000000000000000000000000000..257b8c29c8ead2324a99166bfb6af1ed1fb0e5a5
GIT binary patch
literal 19
UcmWGAGd5B%Hno5NAV-l404Om7!T<mO

literal 0
HcmV?d00001

diff --git a/Tests/test_file_ppm.py b/Tests/test_file_ppm.py
index cda6ec164..16ecb3db4 100644
--- a/Tests/test_file_ppm.py
+++ b/Tests/test_file_ppm.py
@@ -44,6 +44,18 @@ class TestFilePpm(PillowTestCase):
         self.assertRaises(ValueError, lambda: Image.open(path))
 
 
+    def test_neg_ppm(self):
+        """test_neg_ppm
+
+        Storage.c accepted negative values for xsize, ysize.
+        open_ppm is a core debugging item that doesn't check any parameters for
+        sanity. 
+        """
+        
+        with self.assertRaises(ValueError):
+            Image.core.open_ppm('Tests/images/negative_size.ppm')
+
+
 if __name__ == '__main__':
     unittest.main()
 
diff --git a/libImaging/Storage.c b/libImaging/Storage.c
index f40840671..27661bfdb 100644
--- a/libImaging/Storage.c
+++ b/libImaging/Storage.c
@@ -406,6 +406,10 @@ ImagingNew(const char* mode, int xsize, int ysize)
     } else
         bytes = strlen(mode); /* close enough */
 
+    if (xsize < 0 || ysize < 0) {
+        return (Imaging) ImagingError_ValueError("bad image size");
+    }
+
     if ((int64_t) xsize * (int64_t) ysize <= THRESHOLD / bytes) {
         im = ImagingNewBlock(mode, xsize, ysize);
         if (im)