sw: be more careful with sysfs attributes

in case the device still has the FTDI VID and PID, the ftdi_sio module might be loaded, in which case some of the udev matches will not have attributes such as "busnum", "devnum" (and certainly not "serial"). We can be more careful by checking if udev_device_get_sysattr_value() returns NULL before doing the strcpy() to avoid segfaults.

sw: be more careful with sysfs attributes
in case the device still has the FTDI VID and PID, the ftdi_sio module might be loaded, in which case some of the udev matches will not have attributes such as "busnum", "devnum" (and certainly not "serial"). We can be more careful by checking if udev_device_get_sysattr_value() returns NULL before doing the strcpy() to avoid segfaults.
ed89ad4c · Dimitris Lampridis · b6339620 · ed89ad4c
Commit ed89ad4c authored Apr 27, 2023 by Dimitris Lampridis
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Showing with 21 additions and 9 deletions

usb-enum.c software/lib/usb-enum.c +21 -9

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--- a/software/lib/usb-enum.c
+++ b/software/lib/usb-enum.c
@@ -43,15 +43,27 @@ struct oattnusb_devarray *oattnusb_get_devarray(unsigned int vendor_id, unsigned
 			goto out;
 		const char *path = udev_list_entry_get_name(ptr);
 		struct udev_device *dev = udev_device_new_from_syspath(udev, path);
-		struct oattnusb_usb_dev *entry = &usb_dev[found_devs];
-		strcpy(entry->path, path);
-		strcpy(entry->busnum, udev_device_get_sysattr_value(dev, "busnum"));
-		strcpy(entry->devnum, udev_device_get_sysattr_value(dev, "devnum"));
-		strcpy(entry->devno, udev_device_get_sysattr_value(dev, "dev"));
-		strcpy(entry->serial, udev_device_get_sysattr_value(dev, "serial"));
-		strcpy(entry->busport, rindex(entry->path, '/') + 1);
-		
-		found_devs += 1;
+		const char *busnum = udev_device_get_sysattr_value(dev, "busnum");
+		const char *devnum = udev_device_get_sysattr_value(dev, "devnum");
+
+		if (busnum && devnum) {
+			const char *devno = udev_device_get_sysattr_value(dev, "dev");
+			const char *serial = udev_device_get_sysattr_value(dev, "serial");
+			struct oattnusb_usb_dev *entry = &usb_dev[found_devs];
+			strcpy(entry->path, path);
+			strcpy(entry->busnum, busnum);
+			strcpy(entry->devnum, devnum);
+			strcpy(entry->devno, devno);
+			if (serial) {
+				strcpy(entry->serial, serial);
+			}
+			else {
+				strcpy(entry->serial, "EMPTY");
+			}
+			strcpy(entry->busport, rindex(entry->path, '/') + 1);
+
+			found_devs += 1;
+		}
 		udev_device_unref(dev);
 	}
 out: