From 85102ba58b4125ebad941d7555c3c248b23efd16 Mon Sep 17 00:00:00 2001 From: Wang Hai Date: Wed, 16 Jun 2021 12:23:24 +0800 Subject: [PATCH] samples/bpf: Fix Segmentation fault for xdp_redirect command A Segmentation fault error is caused when the following command is executed. $ sudo ./samples/bpf/xdp_redirect lo Segmentation fault This command is missing a device as an argument, resulting in out-of-bounds access from argv. If the number of devices for the xdp_redirect parameter is not 2, we should report an error and exit. Fixes: 24251c264798 ("samples/bpf: add option for native and skb mode for redirect apps") Signed-off-by: Wang Hai Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210616042324.314832-1-wanghai38@huawei.com --- samples/bpf/xdp_redirect_user.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/samples/bpf/xdp_redirect_user.c b/samples/bpf/xdp_redirect_user.c index 41d705c3a1f7..eb876629109a 100644 --- a/samples/bpf/xdp_redirect_user.c +++ b/samples/bpf/xdp_redirect_user.c @@ -130,7 +130,7 @@ int main(int argc, char **argv) if (!(xdp_flags & XDP_FLAGS_SKB_MODE)) xdp_flags |= XDP_FLAGS_DRV_MODE; - if (optind == argc) { + if (optind + 2 != argc) { printf("usage: %s _IN _OUT\n", argv[0]); return 1; }