selftests/net: in timestamping, strncpy needs to preserve null byte

[ Upstream commit 8027bc0307 ]

If user passed an interface option longer than 15 characters, then
device.ifr_name and hwtstamp.ifr_name became non-null-terminated
strings. The compiler warned about this:

timestamping.c:353:2: warning: ‘strncpy’ specified bound 16 equals \
destination size [-Wstringop-truncation]
  353 |  strncpy(device.ifr_name, interface, sizeof(device.ifr_name));

Fixes: cb9eff0978 ("net: new user space API for time stamping of incoming and outgoing packets")
Signed-off-by: Tanner Love <tannerlove@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
tannerlove 2020-06-08 15:37:15 -04:00 committed by Greg Kroah-Hartman
parent 04017f6617
commit dbc1d98be1

View file

@ -332,10 +332,16 @@ int main(int argc, char **argv)
int val;
socklen_t len;
struct timeval next;
size_t if_len;
if (argc < 2)
usage(0);
interface = argv[1];
if_len = strlen(interface);
if (if_len >= IFNAMSIZ) {
printf("interface name exceeds IFNAMSIZ\n");
exit(1);
}
for (i = 2; i < argc; i++) {
if (!strcasecmp(argv[i], "SO_TIMESTAMP"))
@ -369,12 +375,12 @@ int main(int argc, char **argv)
bail("socket");
memset(&device, 0, sizeof(device));
strncpy(device.ifr_name, interface, sizeof(device.ifr_name));
memcpy(device.ifr_name, interface, if_len + 1);
if (ioctl(sock, SIOCGIFADDR, &device) < 0)
bail("getting interface IP address");
memset(&hwtstamp, 0, sizeof(hwtstamp));
strncpy(hwtstamp.ifr_name, interface, sizeof(hwtstamp.ifr_name));
memcpy(hwtstamp.ifr_name, interface, if_len + 1);
hwtstamp.ifr_data = (void *)&hwconfig;
memset(&hwconfig, 0, sizeof(hwconfig));
hwconfig.tx_type =