From 2453afe3845523d9dfe89dbfb3d71abfa095e260 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 12 Nov 2021 07:33:01 +0530 Subject: [PATCH] samples/bpf: Fix incorrect use of strlen in xdp_redirect_cpu Commit b599015f044d ("samples/bpf: Fix application of sizeof to pointer") tried to fix a bug where sizeof was incorrectly applied to a pointer instead of the array string was being copied to, to find the destination buffer size, but ended up using strlen, which is still incorrect. However, on closer look ifname_buf has no other use, hence directly use optarg. Fixes: b599015f044d ("samples/bpf: Fix application of sizeof to pointer") Fixes: e531a220cc59 ("samples: bpf: Convert xdp_redirect_cpu to XDP samples helper") Signed-off-by: Kumar Kartikeya Dwivedi Signed-off-by: Daniel Borkmann Reviewed-by: Alexander Lobakin Tested-by: Alexander Lobakin Link: https://lore.kernel.org/bpf/20211112020301.528357-1-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- samples/bpf/xdp_redirect_cpu_user.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c index d84e6949007c..a81704d3317b 100644 --- a/samples/bpf/xdp_redirect_cpu_user.c +++ b/samples/bpf/xdp_redirect_cpu_user.c @@ -309,7 +309,6 @@ int main(int argc, char **argv) const char *mprog_filename = NULL, *mprog_name = NULL; struct xdp_redirect_cpu *skel; struct bpf_map_info info = {}; - char ifname_buf[IF_NAMESIZE]; struct bpf_cpumap_val value; __u32 infosz = sizeof(info); int ret = EXIT_FAIL_OPTION; @@ -390,10 +389,10 @@ int main(int argc, char **argv) case 'd': if (strlen(optarg) >= IF_NAMESIZE) { fprintf(stderr, "-d/--dev name too long\n"); + usage(argv, long_options, __doc__, mask, true, skel->obj); goto end_cpu; } - safe_strncpy(ifname_buf, optarg, strlen(ifname_buf)); - ifindex = if_nametoindex(ifname_buf); + ifindex = if_nametoindex(optarg); if (!ifindex) ifindex = strtoul(optarg, NULL, 0); if (!ifindex) {