[patch] patch to npw-viewer.c, to prevent segfaults crashing app

0002-prevent-segfaults-in-libraries-crashing-npviewer.patch (text/plain), 2.68 KB, created by Jamal Natour on 2008-03-09 19:49:45 UTC

--- src/npw-viewer.orig	2008-03-09 18:33:51.000000000 +0000
+++ src/npw-viewer.c	2008-03-09 19:03:27.000000000 +0000
@@ -28,6 +28,8 @@
 #include <dlfcn.h>
 #include <unistd.h>
 #include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 
 #include <X11/X.h>
 #include <X11/Xlib.h>
@@ -3199,34 +3201,65 @@ int main(int argc, char **argv)
 	  --argc;
   }
 
+
   // Open plug-in and get exported lib functions
   void *handle = NULL;
+#define EXIT_TRUE  0
+#define EXIT_FALSE 1
+
   if (plugin_path == NULL)
 	cmd = CMD_HELP;
   else {
+  	pid_t pid;
 	const char *error;
 	D(bug("  %s\n", plugin_path));
-	if ((handle = dlopen(plugin_path, RTLD_LAZY)) == NULL) {
-	  npw_printf("ERROR: %s\n", dlerror());
-	  return 1;
-	}
-	dlerror();
-	g_plugin_NP_GetMIMEDescription = (NP_GetMIMEDescriptionUPP)dlsym(handle, "NP_GetMIMEDescription");
-	if ((error = dlerror()) != NULL) {
-	  npw_printf("ERROR: %s\n", error);
-	  return 1;
-	}
-	g_plugin_NP_Initialize = (NP_InitializeUPP)dlsym(handle, "NP_Initialize");
-	if ((error = dlerror()) != NULL) {
-	  npw_printf("ERROR: %s\n", error);
-	  return 1;
-	}
-	g_plugin_NP_Shutdown = (NP_ShutdownUPP)dlsym(handle, "NP_Shutdown");
-	if ((error = dlerror()) != NULL) {
-	  npw_printf("ERROR: %s\n", error);
-	  return 1;
+
+	/* test opening the libary in a child process to prevent a dodgy libary crashing app */
+	if(0 > (pid = fork()))
+		return 1;
+
+	/* IN Child */
+	if(!pid) {
+		/* this line may throw SIGSEGV */
+		if(NULL == (handle = dlopen(plugin_path, RTLD_LAZY)))
+			exit(EXIT_FALSE);
+
+		dlclose(handle);
+		exit(EXIT_TRUE );
+	}
+	else {
+		/* parent */
+		int status;
+		if(0 >(pid = waitpid(pid,&status,0)))
+			return 1;
+
+		if(status != EXIT_TRUE)
+			return 1;
+	
+		/* dlopen() will not seqfault, should be good to go */
+		if ((handle = dlopen(plugin_path, RTLD_LAZY)) == NULL) {
+		  npw_printf("ERROR: %s\n", dlerror());
+		  return 1;
+		}
+		dlerror();
+		g_plugin_NP_GetMIMEDescription = (NP_GetMIMEDescriptionUPP)dlsym(handle, "NP_GetMIMEDescription");
+		if ((error = dlerror()) != NULL) {
+	  		npw_printf("ERROR: %s\n", error);
+	  		return 1;
+		}
+		g_plugin_NP_Initialize = (NP_InitializeUPP)dlsym(handle, "NP_Initialize");
+		if ((error = dlerror()) != NULL) {
+	  		npw_printf("ERROR: %s\n", error);
+	 		 return 1;
+		}
+		g_plugin_NP_Shutdown = (NP_ShutdownUPP)dlsym(handle, "NP_Shutdown");
+		if ((error = dlerror()) != NULL) {
+	  		npw_printf("ERROR: %s\n", error);
+	  		return 1;
+		}
+		g_plugin_NP_GetValue = (NP_GetValueUPP)dlsym(handle, "NP_GetValue");
 	}
-	g_plugin_NP_GetValue = (NP_GetValueUPP)dlsym(handle, "NP_GetValue");
+  
   }
 
   int ret = 1;
@@ -3249,3 +3282,6 @@ int main(int argc, char **argv)
 	dlclose(handle);
   return ret;
 }
+
+
+