From 9f8961c4754dc9a1de486d6dabd41484fc6c54a8 Mon Sep 17 00:00:00 2001
From: Eduardo Silva <eduardo@treasure-data.com>
Date: Wed, 29 May 2019 12:14:28 -0600
Subject: [PATCH] mem: do not permit zero-sized allocations (FLU-01-002)

note: security audit report by Cure53/CNCF

Signed-off-by: Eduardo Silva <eduardo@treasure-data.com>
---
 include/fluent-bit/flb_mem.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/fluent-bit/flb_mem.h b/include/fluent-bit/flb_mem.h
index 7c62d850431..8022a7f16f5 100644
--- a/include/fluent-bit/flb_mem.h
+++ b/include/fluent-bit/flb_mem.h
@@ -55,6 +55,10 @@ static inline ALLOCSZ_ATTR(1)
 void *flb_malloc(const size_t size) {
     void *aux;
 
+    if (size == 0) {
+        return NULL;
+    }
+
     aux = malloc(size);
     if (flb_unlikely(!aux && size)) {
         return NULL;
@@ -67,6 +71,10 @@ static inline ALLOCSZ_ATTR(1)
 void *flb_calloc(size_t n, const size_t size) {
     void *buf;
 
+    if (size == 0) {
+        return NULL;
+    }
+
     buf = calloc(n, size);
     if (flb_unlikely(!buf)) {
         return NULL;
@@ -80,6 +88,13 @@ void *flb_realloc(void *ptr, const size_t size)
 {
     void *aux;
 
+    if (size == 0) {
+        if (ptr) {
+            free(ptr);
+        }
+        return NULL;
+    }
+
     aux = realloc(ptr, size);
     if (flb_unlikely(!aux && size)) {
         return NULL;