https://bugs.gentoo.org/364667

clean up random buffer overflows in the code

--- a/src/backend/back_linux.c
+++ b/src/backend/back_linux.c
@@ -42,7 +42,9 @@ static int probe_devices();
 static int check_driver()
 {
 	FILE *proc;
-	char buffer[80];
+	char *buffer = NULL;
+	size_t len;
+	int ret = 0;
 
 	proc = fopen("/proc/modules", "r");
 
@@ -50,9 +52,9 @@ static int check_driver()
 	if(proc == NULL)
 		return 0;
 
-	while(fgets(buffer, 80, proc) != NULL)
+	while(getline(&buffer, &len, proc) != -1)
 	{
-		char name[80];
+		char name[100];
 		int size;
 		int used;
 
@@ -64,26 +66,23 @@ static int check_driver()
 		{
 			if(strcmp(name, "NVdriver") == 0)
 			{
-				fclose(proc);
 				if(used)
-					return 1;
-
-					return 0;
+					ret = 1;
+				break;
 			}
 
 			if(strcmp(name, "nvidia") == 0)
 			{
-				fclose(proc);
 				if(used)
-					return 2;
-
-				return 0;
+					ret = 2;
+				break;
 			}
 		}
 	}
+	free(buffer);
 	fclose(proc);
 
-	return 0;
+	return ret;
 }
 
 int init_nvclock()
@@ -114,7 +113,8 @@ static int probe_devices()
 {
 	int dev, irq, reg_addr, i=0;
 	unsigned short devbusfn;
-	char buf[256];
+	char *buf = NULL;
+	size_t len;
 	FILE *proc;
 
 	proc = fopen("/proc/bus/pci/devices", "r");
@@ -124,7 +124,7 @@ static int probe_devices()
 		return 0;
 	}
 
-	while(fgets(buf, sizeof(buf)-1, proc)) 
+	while(getline(&buf, &len, proc) != -1)
 	{
 		if(sscanf(buf,"%hx %x %x %x",&devbusfn, &dev, &irq, &reg_addr) != 4) continue;
 
@@ -181,6 +181,7 @@ static int probe_devices()
 			i++;
 		}
 	}
+	free(buf);
 	fclose(proc);
     
 	if(i==0)
--- a/src/backend/config.c
+++ b/src/backend/config.c
@@ -286,8 +286,9 @@ int open_config()
 	{
 		if(mkdir(nvclock.path, 0755))
 		{
-			char buf[80];
-			sprintf(buf, "Can't create '%s'. Do you have sufficient permissions?\n", nvclock.path);
+			char buf[1024];
+			snprintf(buf, sizeof(buf), "Can't create path (do you have sufficient permissions?): %s", nvclock.path);
+			buf[sizeof(buf) - 1] = '\0';
 			set_error_str(buf);
 			return 0;
 		}
@@ -297,8 +298,9 @@ int open_config()
 	/* Check if .nvclock really is a directory. For some users it was a file and this led to a segfault. */
 	if(!S_ISDIR(stat_buf.st_mode))
 	{
-		char buf[80];
-		sprintf(buf, "Can't open '%s'. Is it really a directory?\n", nvclock.path);
+		char buf[1024];
+		snprintf(buf, sizeof(buf), "Can't open path (Is it really a directory?): %s", nvclock.path);
+		buf[sizeof(buf) - 1] = '\0';
 		set_error_str(buf);
 		return 0;
 	}
--- a/src/backend/error.c
+++ b/src/backend/error.c
@@ -41,23 +41,19 @@ void set_error_str(const char *str)
 }
 
 
-char *get_error(char *buf, int size)
+const char *get_error(void)
 {
 	switch(nvclock.nv_errno)
 	{
 		case NV_ERR_NO_DEVICES_FOUND:
-			strcpy(buf, "No nvidia cards found in your system!");
-			break;
+			return "No nvidia cards found in your system!";
 		case NV_ERR_NO_DRIVERS_FOUND:
-			strcpy(buf, "You don't have enough permissions to run NVClock! Retry as root or install the Nvidia drivers.");
-			break;
+			return "You don't have enough permissions to run NVClock! Retry as root or install the Nvidia drivers.";
 		case NV_ERR_NOT_ENOUGH_PERMISSIONS:
-			strcpy(buf, "You don't have enough permissions to run NVClock! Retry as root.");
-			break;
+			return "You don't have enough permissions to run NVClock! Retry as root.";
 		case NV_ERR_OTHER:
-			strcpy(buf, nvclock.nv_err_str);
-			break;
+			return nvclock.nv_err_str;
 	}
 
-	return buf;
+	return "unknown";
 }
--- a/src/backend/nvclock.h
+++ b/src/backend/nvclock.h
@@ -335,7 +335,7 @@ cfg_entry* lookup_entry(cfg_entry **cfg, char *section, char *name);
 void destroy(cfg_entry **cfg);
 
 /* error handling */
-char *get_error(char *buf, int size);
+const char *get_error(void);
 void set_error(int code);
 void set_error_str(const char *err);
 
--- a/src/gtk/main.c
+++ b/src/gtk/main.c
@@ -264,8 +264,7 @@ int main (int argc, char *argv[])
 	*/
 	if(!init_nvclock())
 	{
-		char buf[80];
-		GtkWidget *dialog = gtk_message_dialog_new(NULL, GTK_DIALOG_MODAL, GTK_MESSAGE_ERROR, GTK_BUTTONS_CLOSE, "%s", get_error(buf, 80));
+		GtkWidget *dialog = gtk_message_dialog_new(NULL, GTK_DIALOG_MODAL, GTK_MESSAGE_ERROR, GTK_BUTTONS_CLOSE, "%s", get_error());
 		gtk_dialog_run(GTK_DIALOG(dialog));
 		g_signal_connect_swapped(GTK_OBJECT(dialog), "response", G_CALLBACK(gtk_widget_destroy), GTK_OBJECT(dialog));
 		gtk_widget_destroy(dialog);
--- a/src/nvclock.c
+++ b/src/nvclock.c
@@ -604,8 +604,7 @@ int main(int argc, char *argv[])
 
 	if(!init_nvclock())
 	{
-		char buf[80];
-		fprintf(stderr, "Error: %s\n", get_error(buf, 80));
+		fprintf(stderr, "Error: %s\n", get_error());
 		return 0;
 	}
 
@@ -851,8 +850,7 @@ int main(int argc, char *argv[])
 		{
 			if(!set_card(i))
 			{
-				char buf[80];
-				fprintf(stderr, "Error: %s\n", get_error(buf, 80));
+				fprintf(stderr, "Error: %s\n", get_error());
 				return 0;
 			}
 
@@ -887,8 +885,7 @@ int main(int argc, char *argv[])
 	/* set the card object to the requested card */
 	if(!set_card(card_number))
 	{
-		char buf[80];
-		fprintf(stderr, "Error: %s\n", get_error(buf, 80));
+		fprintf(stderr, "Error: %s\n", get_error());
 		return 0;
 	}