[PATCH] libc/stddef/malloc/realloc.c: Fix failure when doing realloc(mem, -1).

James Coleman james.coleman at ubicom.com
Thu Jul 30 18:45:16 UTC 2009


Now check that new_size is > ((unsigned long)-(MALLOC_HEADER_SIZE*2)),
which is the same test that is found in malloc.

This fixes a test failure in test/malloc/tst-mcheck.

Signed-off-by: James Coleman <jcoleman at ubicom.com>
---
 libc/stdlib/malloc/realloc.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/libc/stdlib/malloc/realloc.c b/libc/stdlib/malloc/realloc.c
index a827199..10c580c 100644
--- a/libc/stdlib/malloc/realloc.c
+++ b/libc/stdlib/malloc/realloc.c
@@ -27,8 +27,10 @@ realloc (void *mem, size_t new_size)
   size_t size;
   char *base_mem;
 
-  /* Check for special cases.  */
-  if (! new_size)
+  /* Check for special cases, such as realloc(mem, 0) or if they are
+     doing something dumb like realloc(mem, -1) */
+  if (unlikely(! new_size) ||
+      unlikely(((unsigned long)new_size > (unsigned long)(MALLOC_HEADER_SIZE*-2)))))
     {
       free (mem);
       return malloc (new_size);
-- 
1.6.1.1



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