Closes #15897: zipimport.c doesn't check return value of fseek()
diff --git a/Modules/zipimport.c b/Modules/zipimport.c
index b7a1b8d..7240cb4 100644
--- a/Modules/zipimport.c
+++ b/Modules/zipimport.c
@@ -709,7 +709,12 @@
"'%.200s'", 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: %s", archive);
+ return NULL;
+ }
header_position = ftell(fp);
if (fread(endof_central_dir, 1, 22, fp) != 22) {
fclose(fp);
@@ -743,11 +748,13 @@
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 + 10, 0);
+ if (fseek(fp, header_offset + 10, 0) == -1)
+ goto fseek_error;
compress = PyMarshal_ReadShortFromFile(fp);
time = PyMarshal_ReadShortFromFile(fp);
date = PyMarshal_ReadShortFromFile(fp);
@@ -758,7 +765,8 @@
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;
@@ -790,6 +798,11 @@
PySys_WriteStderr("# zipimport: found %ld names in %s\n",
count, archive);
return files;
+fseek_error:
+ fclose(fp);
+ Py_XDECREF(files);
+ PyErr_Format(ZipImportError, "can't read Zip file: %s", archive);
+ return NULL;
error:
fclose(fp);
Py_XDECREF(files);
@@ -857,7 +870,12 @@
}
/* 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: %s", archive);
+ return NULL;
+ }
+
l = PyMarshal_ReadLongFromFile(fp);
if (l != 0x04034B50) {
/* Bad: Local File Header */
@@ -867,7 +885,12 @@
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: %s", archive);
+ return NULL;
+ }
+
l = 30 + PyMarshal_ReadShortFromFile(fp) +
PyMarshal_ReadShortFromFile(fp); /* local header size */
file_offset += l; /* Start of file data */
@@ -881,8 +904,13 @@
buf = PyString_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: %s", archive);
+ return NULL;
+ }
fclose(fp);
if (err || bytes_read != data_size) {
PyErr_SetString(PyExc_IOError,