From: Ben Hutchings Date: Fri, 20 Jul 2018 01:30:24 +0100 Subject: usbip: Fix misuse of strncpy() Bug-Debian: https://bugs.debian.org/897802 Forwarded: https://marc.info/?l=linux-usb&m=153213915806258 gcc 8 reports: usbip_device_driver.c: In function ‘read_usb_vudc_device’: usbip_device_driver.c:106:2: error: ‘strncpy’ specified bound 256 equals destination size [-Werror=stringop-truncation] strncpy(dev->path, path, SYSFS_PATH_MAX); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ usbip_device_driver.c:125:2: error: ‘strncpy’ specified bound 32 equals destination size [-Werror=stringop-truncation] strncpy(dev->busid, name, SYSFS_BUS_ID_SIZE); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I'm not convinced it makes sense to truncate the copied strings here, but since we're already doing so let's ensure they're still null- terminated. We can't easily use strlcpy() here, so use snprintf(). usbip_common.c has the same problem. Signed-off-by: Ben Hutchings --- Index: linux/tools/usb/usbip/libsrc/usbip_common.c =================================================================== --- linux.orig/tools/usb/usbip/libsrc/usbip_common.c +++ linux/tools/usb/usbip/libsrc/usbip_common.c @@ -226,8 +226,8 @@ int read_usb_device(struct udev_device * path = udev_device_get_syspath(sdev); name = udev_device_get_sysname(sdev); - strncpy(udev->path, path, SYSFS_PATH_MAX); - strncpy(udev->busid, name, SYSFS_BUS_ID_SIZE); + snprintf(udev->path, SYSFS_PATH_MAX, "%s", path); + snprintf(udev->busid, SYSFS_BUS_ID_SIZE, "%s", name); sscanf(name, "%u-%u", &busnum, &devnum); udev->busnum = busnum; Index: linux/tools/usb/usbip/libsrc/usbip_device_driver.c =================================================================== --- linux.orig/tools/usb/usbip/libsrc/usbip_device_driver.c +++ linux/tools/usb/usbip/libsrc/usbip_device_driver.c @@ -103,7 +103,7 @@ int read_usb_vudc_device(struct udev_dev copy_descr_attr16(dev, &descr, idProduct); copy_descr_attr16(dev, &descr, bcdDevice); - strncpy(dev->path, path, SYSFS_PATH_MAX); + snprintf(dev->path, SYSFS_PATH_MAX, "%s", path); dev->speed = USB_SPEED_UNKNOWN; speed = udev_device_get_sysattr_value(sdev, "current_speed"); @@ -122,7 +122,7 @@ int read_usb_vudc_device(struct udev_dev dev->busnum = 0; name = udev_device_get_sysname(plat); - strncpy(dev->busid, name, SYSFS_BUS_ID_SIZE); + snprintf(dev->busid, SYSFS_BUS_ID_SIZE, "%s", name); return 0; err: fclose(fd);