From d59dd69d5576d699d7d3f5da0b4738c3a36d0133 Mon Sep 17 00:00:00 2001 From: "Daniel T. Lee" Date: Mon, 3 Dec 2018 19:39:30 +0900 Subject: [PATCH] samples: bpf: fix: seg fault with NULL pointer arg When NULL pointer accidentally passed to write_kprobe_events, due to strlen(NULL), segmentation fault happens. Changed code returns -1 to deal with this situation. Bug issued with Smatch, static analysis. Signed-off-by: Daniel T. Lee Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- samples/bpf/bpf_load.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c index 434ea34a5954..eae7b635343d 100644 --- a/samples/bpf/bpf_load.c +++ b/samples/bpf/bpf_load.c @@ -58,7 +58,9 @@ static int write_kprobe_events(const char *val) { int fd, ret, flags; - if ((val != NULL) && (val[0] == '\0')) + if (val == NULL) + return -1; + else if (val[0] == '\0') flags = O_WRONLY | O_TRUNC; else flags = O_WRONLY | O_APPEND; -- 2.30.2