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| author | tannerlove <tannerlove@google.com> | 2020-06-08 22:37:15 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-06-09 05:14:28 +0300 |
| commit | 8027bc0307ce59759b90679fa5d8b22949586d20 (patch) | |
| tree | da2e4e5a555eedbca6564fbcd18f7ef0fd7d8956 | |
| parent | 07a86b01c07c315d9b8eeb0009a9123af3d7dd4b (diff) | |
| download | linux-8027bc0307ce59759b90679fa5d8b22949586d20.tar.xz | |
selftests/net: in timestamping, strncpy needs to preserve null byte
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: cb9eff097831 ("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>
| -rw-r--r-- | tools/testing/selftests/net/timestamping.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/tools/testing/selftests/net/timestamping.c b/tools/testing/selftests/net/timestamping.c index aca3491174a1..f4bb4fef0f39 100644 --- a/tools/testing/selftests/net/timestamping.c +++ b/tools/testing/selftests/net/timestamping.c @@ -313,10 +313,16 @@ 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")) @@ -350,12 +356,12 @@ 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 = |