Changeset 50356

Timestamp:

02/16/2021 06:46:21 PM (4 years ago)

Author:

SergeyBiryukov

Message:

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

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.

Props yakimun, fierevere, jrf, DavidAnderson, SergeyBiryukov.
Merges [50355] to the 5.6 branch.
Fixes #52018.

Location:

branches/5.6

Files:

• . (modified) (1 prop)
• src/wp-admin/includes/class-pclzip.php (modified) (4 diffs)

branches/5.6/src/wp-admin/includes/class-pclzip.php

@@ -3885 +3885 @@
 
             // ----- Read the compressed file in a buffer (one shot)
-            $v_buffer = @fread($this->zip_fd, $p_entry['compressed_size']);
+            if ( $p_entry['compressed_size'] > 0 ) {
+              $v_buffer = @fread($this->zip_fd, $p_entry['compressed_size']);
+            }
+            else {
+              $v_buffer = false;
+            }
 
             // ----- Decompress the file
@@ -4097 +4102 @@
 
           // ----- Read the file in a buffer (one shot)
-          $v_buffer = @fread($this->zip_fd, $p_entry['compressed_size']);
+          if ( $p_entry['compressed_size'] > 0 ) {
+            $v_buffer = @fread($this->zip_fd, $p_entry['compressed_size']);
+          }
+          else {
+            $v_buffer = false;
+          }
 
           // ----- Send the file to the output
@@ -4106 +4116 @@
 
           // ----- Read the compressed file in a buffer (one shot)
-          $v_buffer = @fread($this->zip_fd, $p_entry['compressed_size']);
+          if ( $p_entry['compressed_size'] > 0 ) {
+            $v_buffer = @fread($this->zip_fd, $p_entry['compressed_size']);
+          }
+          else {
+            $v_buffer = false;
+          }
 
           // ----- Decompress the file
@@ -4210 +4225 @@
 
           // ----- Reading the file
-          $p_string = @fread($this->zip_fd, $p_entry['compressed_size']);
+          if ( $p_entry['compressed_size'] > 0 ) {
+            $p_string = @fread($this->zip_fd, $p_entry['compressed_size']);
+          }
+          else {
+            $p_string = false;
+          }
         }
         else {
 
           // ----- Reading the file
-          $v_data = @fread($this->zip_fd, $p_entry['compressed_size']);
+          if ( $p_entry['compressed_size'] > 0 ) {
+            $v_data = @fread($this->zip_fd, $p_entry['compressed_size']);
+          }
+          else {
+            $v_data = false;
+          }
 
           // ----- Decompress the file