From: Chet Ramey <chet.ramey@case.edu>
Date: Wed, 17 Nov 2021 21:44:19 +0000 (-0500)
Subject: Bash-5.1 patch 9: fix bash malloc implementation of malloc_usable_size
X-Git-Tag: bash-5.2-alpha~8
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fed42742e0b33b358610bf62c7474f55e6465205;p=thirdparty%2Fbash.git

Bash-5.1 patch 9: fix bash malloc implementation of malloc_usable_size
---

diff --git a/lib/malloc/malloc.c b/lib/malloc/malloc.c
index 439f8ef11..92e6efa52 100644
--- a/lib/malloc/malloc.c
+++ b/lib/malloc/malloc.c
@@ -1286,13 +1286,12 @@ malloc_usable_size (mem)
       p = (union mhead *) ap - 1;
     }
 
-  /* XXX - should we return 0 if ISFREE? */
-  maxbytes = binsize(p->mh_index);
-
-  /* So the usable size is the maximum number of bytes in the bin less the
-     malloc overhead */
-  maxbytes -= MOVERHEAD + MSLOP;
-  return (maxbytes);
+  /* return 0 if ISFREE */
+  if (p->mh_alloc == ISFREE)
+    return 0;
+  
+  /* Since we use bounds checking, the usable size is the last requested size. */
+  return (p->mh_nbytes);
 }
 
 #if !defined (NO_VALLOC)
diff --git a/patchlevel.h b/patchlevel.h
index 10fde2eee..17586ff7f 100644
--- a/patchlevel.h
+++ b/patchlevel.h
@@ -25,6 +25,6 @@
    regexp `^#define[ 	]*PATCHLEVEL', since that's what support/mkversion.sh
    looks for to find the patch level (for the sccs version string). */
 
-#define PATCHLEVEL 8
+#define PATCHLEVEL 9
 
 #endif /* _PATCHLEVEL_H_ */