tracing/kprobes: Fix NULL pointer dereference in trace_kprobe_create()

[linux.git] / kernel / trace / trace_kprobe.c

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 5c19b8c41c7e706efb8da85d6b4d45a3931d2a3c..d5fb09ebba8b79da9e82bc6d23fc48e8d1a02274 100644 (file)
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -607,11 +607,17 @@ static int trace_kprobe_create(int argc, const char *argv[])
        char buf[MAX_EVENT_NAME_LEN];
        unsigned int flags = TPARG_FL_KERNEL;
 
-       /* argc must be >= 1 */
-       if (argv[0][0] == 'r') {
+       switch (argv[0][0]) {
+       case 'r':
                is_return = true;
                flags |= TPARG_FL_RETURN;
-       } else if (argv[0][0] != 'p' || argc < 2)
+               break;
+       case 'p':
+               break;
+       default:
+               return -ECANCELED;
+       }
+       if (argc < 2)
                return -ECANCELED;
 
        event = strchr(&argv[0][1], ':');