On Mon, Dec 3, 2018 at 2:40 AM Daniel T. Lee <danieltim...@gmail.com> wrote:
>
> 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 <danieltim...@gmail.com>
Acked-by: Song Liu <songliubrav...@fb.com>
> ---
> 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;
> --
> 2.17.1
>
