1 files changed, 6 insertions, 1 deletions

diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index f96f0383f6c6..ad1d6164e946 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -36,6 +36,10 @@ struct trace_bprintk_fmt {
 static inline struct trace_bprintk_fmt *lookup_format(const char *fmt)
 {
         struct trace_bprintk_fmt *pos;
+
+        if (!fmt)
+                return ERR_PTR(-EINVAL);
+
         list_for_each_entry(pos, &trace_bprintk_fmt_list, list) {
                 if (!strcmp(pos->fmt, fmt))
                         return pos;
@@ -57,7 +61,8 @@ void hold_module_trace_bprintk_format(const char **start, const char **end)
         for (iter = start; iter < end; iter++) {
                 struct trace_bprintk_fmt *tb_fmt = lookup_format(*iter);
                 if (tb_fmt) {
-                        *iter = tb_fmt->fmt;
+                        if (!IS_ERR(tb_fmt))
+                                *iter = tb_fmt->fmt;
                         continue;
                 }