Changeset 51694

Timestamp:

08/30/2021 02:27:48 PM (3 years ago)

Author:

desrosj

Message:

Filesystem API: Make sure to only call fread() on non-empty files in PclZip::privAddFile().

This avoids a fatal error on PHP 8 caused by passing a zero value to fread() as the $length argument, which must be greater than zero.

This commit also amends the previous solution for similar issues elsewhere in the file to ensure consistent type for string values, instead of changing the type from string to bool when trying to read from an empty file.

Follow-up to [50355].

Props DavidAnderson, jrf, SergeyBiryukov.
Merges [51686] to the 5.8 branch.
Fixes #54036.

Location:

branches/5.8

Files:

• . (modified) (1 prop)
• src/wp-admin/includes/class-pclzip.php (modified) (6 diffs)

branches/5.8/src/wp-admin/includes/class-pclzip.php

@@ -2675 +2675 @@
 
         // ----- Read the file content
-        $v_content = @fread($v_file, $p_header['size']);
+        if ($p_header['size'] > 0) {
+          $v_content = @fread($v_file, $p_header['size']);
+        }
+        else {
+          $v_content = '';
+        }
 
         // ----- Close the file
@@ -3885 +3890 @@
 
             // ----- Read the compressed file in a buffer (one shot)
-            if ( $p_entry['compressed_size'] > 0 ) {
+            if ($p_entry['compressed_size'] > 0) {
               $v_buffer = @fread($this->zip_fd, $p_entry['compressed_size']);
             }
             else {
-              $v_buffer = false;
+              $v_buffer = '';
             }
 
@@ -4102 +4107 @@
 
           // ----- Read the file in a buffer (one shot)
-          if ( $p_entry['compressed_size'] > 0 ) {
+          if ($p_entry['compressed_size'] > 0) {
             $v_buffer = @fread($this->zip_fd, $p_entry['compressed_size']);
           }
           else {
-            $v_buffer = false;
+            $v_buffer = '';
           }
 
@@ -4116 +4121 @@
 
           // ----- Read the compressed file in a buffer (one shot)
-          if ( $p_entry['compressed_size'] > 0 ) {
+          if ($p_entry['compressed_size'] > 0) {
             $v_buffer = @fread($this->zip_fd, $p_entry['compressed_size']);
           }
           else {
-            $v_buffer = false;
+            $v_buffer = '';
           }
 
@@ -4225 +4230 @@
 
           // ----- Reading the file
-          if ( $p_entry['compressed_size'] > 0 ) {
+          if ($p_entry['compressed_size'] > 0) {
             $p_string = @fread($this->zip_fd, $p_entry['compressed_size']);
           }
           else {
-            $p_string = false;
+            $p_string = '';
           }
         }
@@ -4235 +4240 @@
 
           // ----- Reading the file
-          if ( $p_entry['compressed_size'] > 0 ) {
+          if ($p_entry['compressed_size'] > 0) {
             $v_data = @fread($this->zip_fd, $p_entry['compressed_size']);
           }
           else {
-            $v_data = false;
+            $v_data = '';
           }