From 3cdef2b892f2049fd8a4d8c5ad4baf0e28ea73c1 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 20 Sep 2012 17:53:03 +0200
Subject: [PATCH] util: fix overflow checks (cherry picked from commit
 aa408e7799cf01f048efedf434916544b4badc77)

---
 src/shared/util.c | 2 +-
 src/shared/util.h | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/shared/util.c b/src/shared/util.c
index 9c189eb..6f2780a 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -1212,7 +1212,7 @@ char *strnappend(const char *s, const char *suffix, size_t b) {
         assert(suffix);
 
         a = strlen(s);
-        if ((size_t) -1 - a > b)
+        if (b > ((size_t) -1) - a)
                 return NULL;
 
         r = new(char, a+b+1);
diff --git a/src/shared/util.h b/src/shared/util.h
index 86f899a..5459810 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -530,14 +530,14 @@ bool is_valid_documentation_url(const char *url);
 bool in_initrd(void);
 
 _malloc_  static inline void *malloc_multiply(size_t a, size_t b) {
-        if (_unlikely_(a > ((size_t) -1) / b))
+        if (_unlikely_(b == 0 || a > ((size_t) -1) / b))
                 return NULL;
 
         return malloc(a * b);
 }
 
 _malloc_ static inline void *memdup_multiply(const void *p, size_t a, size_t b) {
-        if (_unlikely_(a > ((size_t) -1) / b))
+        if (_unlikely_(b == 0 || a > ((size_t) -1) / b))
                 return NULL;
 
         return memdup(p, a * b);