tracing/probe: Check the size of argument name and body

Check the size of argument name and expression is not 0
and smaller than maximum length.

Link: http://lkml.kernel.org/r/155253783029.14922.12650939303827581096.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

2 files changed, 3 insertions, 0 deletions

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 0dc13bff2847..bf9d3d7e0c9d 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -554,6 +554,8 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg,
 
         body = strchr(arg, '=');
         if (body) {
+                if (body - arg > MAX_ARG_NAME_LEN || body == arg)
+                        return -EINVAL;
                 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
                 body++;
         } else {
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 8a63f8bc01bc..2177c206de15 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -32,6 +32,7 @@
 #define MAX_TRACE_ARGS          128
 #define MAX_ARGSTR_LEN          63
 #define MAX_ARRAY_LEN           64
+#define MAX_ARG_NAME_LEN        32
 #define MAX_STRING_SIZE         PATH_MAX
 
 /* Reserved field names */