| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.1 196/371] libbpf: fix GCC8 warning for strncpy | Date | Wed, 24 Jul 2019 21:19:08 +0200 |
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[ Upstream commit cdfc7f888c2a355b01308e97c6df108f1c2b64e8 ]
GCC8 started emitting warning about using strncpy with number of bytes exactly equal destination size, which is generally unsafe, as can lead to non-zero terminated string being copied. Use IFNAMSIZ - 1 as number of bytes to ensure name is always zero-terminated.
Signed-off-by: Andrii Nakryiko <andriin@fb.com> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- tools/lib/bpf/xsk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index af5f310ecca1..1fe0e1eec738 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -336,7 +336,8 @@ static int xsk_get_max_queues(struct xsk_socket *xsk) channels.cmd = ETHTOOL_GCHANNELS; ifr.ifr_data = (void *)&channels; - strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ); + strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1); + ifr.ifr_name[IFNAMSIZ - 1] = '\0'; err = ioctl(fd, SIOCETHTOOL, &ifr); if (err && errno != EOPNOTSUPP) { ret = -errno; -- 2.20.1
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