Re: [PATCH v9 tip 6/9] samples: bpf: simple non-portable kprobe filter example

* Alexei Starovoitov [off-list ref] wrote:

+void read_trace_pipe(void)
+{
+	int trace_fd;
+
+	trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0);
+	if (trace_fd < 0)
+		return;
+
+	while (1) {
+		static char buf[4096];
+		ssize_t sz;
+
+		sz = read(trace_fd, buf, sizeof(buf));

read() will return -1 on failure ...

+		if (sz) {

... this test passes ...

+			buf[sz] = 0;

... and here we smash the stack?

+			puts(buf);
+		}
+	}

Thanks,

	Ingo