[Python-checkins] cpython (merge 3.2 -> 3.3): MERGE: Closes #15897: zipimport.c doesn't check return value of fseek()

[jesus.cea]

http://hg.python.org/cpython/rev/0f1637c4d673
changeset:   79422:0f1637c4d673
branch:      3.3
parent:      79415:fa3dcc8c9e52
parent:      79420:4da48083aaab
user:        Jesus Cea <jcea at jcea.es>
date:        Wed Oct 03 03:00:37 2012 +0200
summary:
  MERGE: Closes #15897: zipimport.c doesn't check return value of fseek()

files:
  Misc/ACKS           |   1 +
  Misc/NEWS           |   3 ++
  Modules/zipimport.c |  43 +++++++++++++++++++++++++++-----
  3 files changed, 40 insertions(+), 7 deletions(-)


diff --git a/Misc/ACKS b/Misc/ACKS
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -246,6 +246,7 @@
 Jeremy Craven
 Laura Creighton
 Simon Cross
+Felipe Cruz
 Drew Csillag
 Joaquin Cuenca Abela
 John Cugini
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -467,6 +467,9 @@
 - Issue #15020: The program name used to search for Python's path is now
   "python3" under Unix, not "python".
 
+- Issue #15897: zipimport.c doesn't check return value of fseek().
+  Patch by Felipe Cruz.
+
 - Issue #15033: Fix the exit status bug when modules invoked using -m swith,
   return the proper failure return value (1). Patch contributed by Jeff Knupp.
 
diff --git a/Modules/zipimport.c b/Modules/zipimport.c
--- a/Modules/zipimport.c
+++ b/Modules/zipimport.c
@@ -875,7 +875,12 @@
             PyErr_Format(ZipImportError, "can't open Zip file: %R", archive);
         return NULL;
     }
-    fseek(fp, -22, SEEK_END);
+
+    if (fseek(fp, -22, SEEK_END) == -1) {
+        fclose(fp);
+        PyErr_Format(ZipImportError, "can't read Zip file: %R", archive);
+        return NULL;
+    }
     header_position = ftell(fp);
     if (fread(endof_central_dir, 1, 22, fp) != 22) {
         fclose(fp);
@@ -904,11 +909,13 @@
         PyObject *t;
         int err;
 
-        fseek(fp, header_offset, 0);  /* Start of file header */
+        if (fseek(fp, header_offset, 0) == -1)  /* Start of file header */
+            goto fseek_error;
         l = PyMarshal_ReadLongFromFile(fp);
         if (l != 0x02014B50)
             break;              /* Bad: Central Dir File Header */
-        fseek(fp, header_offset + 8, 0);
+        if (fseek(fp, header_offset + 8, 0) == -1)
+            goto fseek_error;
         flags = (unsigned short)PyMarshal_ReadShortFromFile(fp);
         compress = PyMarshal_ReadShortFromFile(fp);
         time = PyMarshal_ReadShortFromFile(fp);
@@ -920,7 +927,8 @@
         header_size = 46 + name_size +
            PyMarshal_ReadShortFromFile(fp) +
            PyMarshal_ReadShortFromFile(fp);
-        fseek(fp, header_offset + 42, 0);
+        if (fseek(fp, header_offset + 42, 0) == -1)
+            goto fseek_error;
         file_offset = PyMarshal_ReadLongFromFile(fp) + arc_offset;
         if (name_size > MAXPATHLEN)
             name_size = MAXPATHLEN;
@@ -980,6 +988,12 @@
         PySys_FormatStderr("# zipimport: found %ld names in %R\n",
                            count, archive);
     return files;
+fseek_error:
+    fclose(fp);
+    Py_XDECREF(files);
+    Py_XDECREF(nameobj);
+    PyErr_Format(ZipImportError, "can't read Zip file: %R", archive);
+    return NULL;
 error:
     fclose(fp);
     Py_XDECREF(files);
@@ -1050,7 +1064,12 @@
     }
 
     /* Check to make sure the local file header is correct */
-    fseek(fp, file_offset, 0);
+    if (fseek(fp, file_offset, 0) == -1) {
+        fclose(fp);
+        PyErr_Format(ZipImportError, "can't read Zip file: %R", archive);
+        return NULL;
+    }
+
     l = PyMarshal_ReadLongFromFile(fp);
     if (l != 0x04034B50) {
         /* Bad: Local File Header */
@@ -1060,7 +1079,12 @@
         fclose(fp);
         return NULL;
     }
-    fseek(fp, file_offset + 26, 0);
+    if (fseek(fp, file_offset + 26, 0) == -1) {
+        fclose(fp);
+        PyErr_Format(ZipImportError, "can't read Zip file: %R", archive);
+        return NULL;
+    }
+
     l = 30 + PyMarshal_ReadShortFromFile(fp) +
         PyMarshal_ReadShortFromFile(fp);        /* local header size */
     file_offset += l;           /* Start of file data */
@@ -1077,8 +1101,13 @@
     buf = PyBytes_AsString(raw_data);
 
     err = fseek(fp, file_offset, 0);
-    if (err == 0)
+    if (err == 0) {
         bytes_read = fread(buf, 1, data_size, fp);
+    } else {
+        fclose(fp);
+        PyErr_Format(ZipImportError, "can't read Zip file: %R", archive);
+        return NULL;
+    }
     fclose(fp);
     if (err || bytes_read != data_size) {
         PyErr_SetString(PyExc_IOError,

-- 
Repository URL: http://hg.python.org/cpython