cups-filters/SOURCES/beh-cve2023.patch

diff --git a/backend/beh.c b/backend/beh.c
index 225fd27..5e9cee0 100644
--- a/backend/beh.c
+++ b/backend/beh.c
@@ -22,6 +22,7 @@
 #include "backend-private.h"
 #include <cups/array.h>
 #include <ctype.h>
+#include <sys/wait.h>
 
 /*
  * Local globals...
@@ -213,10 +214,14 @@ call_backend(char *uri,                 /* I - URI of final destination */
 	     char **argv,		/* I - Command-line arguments */
 	     char *filename) {          /* I - File name of input data */
   const char	*cups_serverbin;	/* Location of programs */
+  char          *backend_argv[8];       // Arguments for called CUPS backend
   char		scheme[1024],           /* Scheme from URI */
                 *ptr,			/* Pointer into scheme */
-		cmdline[65536];		/* Backend command line */
-  int           retval;
+		backend_path[2048];	// Backend path
+  int           pid,
+                wait_pid,
+                wait_status,
+                retval = 0;
 
  /*
   * Build the backend command line...
@@ -235,16 +240,19 @@ call_backend(char *uri,                 /* I - URI of final destination */
     fprintf(stderr,
 	    "ERROR: beh: Direct output into a file not supported.\n");
     exit (CUPS_BACKEND_FAILED);
-  } else
-    snprintf(cmdline, sizeof(cmdline),
-	     "%s/backend/%s '%s' '%s' '%s' '%s' '%s' %s",
-	     cups_serverbin, scheme, argv[1], argv[2], argv[3],
-	     /* Apply number of copies only if beh was called with a
-		file name and not with the print data in stdin, as
-	        backends should handle copies only if they are called
-	        with a file name */
-	     (argc == 6 ? "1" : argv[4]),
-	     argv[5], filename);
+  }
+
+  backend_argv[0] = uri;
+  backend_argv[1] = argv[1];
+  backend_argv[2] = argv[2];
+  backend_argv[3] = argv[3];
+  backend_argv[4] = (argc == 6 ? "1" : argv[4]);
+  backend_argv[5] = argv[5];
+  backend_argv[6] = filename;
+  backend_argv[7] = NULL;
+
+  snprintf(backend_path, sizeof(backend_path),
+	   "%s/backend/%s", cups_serverbin, scheme);
 
  /*
   * Overwrite the device URI and run the actual backend...
@@ -253,17 +261,41 @@ call_backend(char *uri,                 /* I - URI of final destination */
   setenv("DEVICE_URI", uri, 1);
 
   fprintf(stderr,
-	  "DEBUG: beh: Executing backend command line \"%s\"...\n",
-	  cmdline);
+	  "DEBUG: beh: Executing backend command line \"%s '%s' '%s' '%s' '%s' '%s'%s%s\"...\n",
+	  backend_path, backend_argv[1], backend_argv[2], backend_argv[3],
+	  backend_argv[4], backend_argv[5],
+	  (backend_argv[6] && backend_argv[6][0] ? " " : ""),
+	  (backend_argv[6] && backend_argv[6][0] ? backend_argv[6] : ""));
   fprintf(stderr,
 	  "DEBUG: beh: Using device URI: %s\n",
 	  uri);
 
-  retval = system(cmdline) >> 8;
+  if ((pid = fork()) == 0)
+  {
+    retval = execv(backend_path, backend_argv);
+
+    if (retval == -1)
+      fprintf(stderr, "ERROR: Unable to execute backend: %s\n",
+	      strerror(errno));
+    exit (CUPS_BACKEND_FAILED);
+  }
+  else if (pid < 0)
+  {
+    fprintf(stderr, "ERROR: Unable to fork for backend\n");
+    return (CUPS_BACKEND_FAILED);
+  }
+
+  while ((wait_pid = wait(&wait_status)) < 0 && errno == EINTR);
 
-  if (retval == -1)
-    fprintf(stderr, "ERROR: Unable to execute backend command line: %s\n",
-	    strerror(errno));
+  if (wait_pid >= 0 && wait_status)
+  {
+    if (WIFEXITED(wait_status))
+      retval = WEXITSTATUS(wait_status);
+    else if (WTERMSIG(wait_status) != SIGTERM)
+      retval = WTERMSIG(wait_status);
+    else
+      retval = 0;
+  }
 
   return (retval);
 }