1 files changed, 7 insertions, 4 deletions

diff --git a/tools/bpf/bpftool/jit_disasm.c b/tools/bpf/bpftool/jit_disasm.c
index 3ef3093560ba..bfed711258ce 100644
--- a/tools/bpf/bpftool/jit_disasm.c
+++ b/tools/bpf/bpftool/jit_disasm.c
@@ -11,6 +11,8 @@
  * Licensed under the GNU General Public License, version 2.0 (GPLv2)
  */
 
+#define _GNU_SOURCE
+#include <stdio.h>
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -44,11 +46,13 @@ static int fprintf_json(void *out, const char *fmt, ...)
         char *s;
 
         va_start(ap, fmt);
+        if (vasprintf(&s, fmt, ap) < 0)
+                return -1;
+        va_end(ap);
+
         if (!oper_count) {
                 int i;
 
-                s = va_arg(ap, char *);
-
                 /* Strip trailing spaces */
                 i = strlen(s) - 1;
                 while (s[i] == ' ')
@@ -61,11 +65,10 @@ static int fprintf_json(void *out, const char *fmt, ...)
         } else if (!strcmp(fmt, ",")) {
                    /* Skip */
         } else {
-                s = va_arg(ap, char *);
                 jsonw_string(json_wtr, s);
                 oper_count++;
         }
-        va_end(ap);
+        free(s);
         return 0;
 }