bind 9.6.0-P1's nsupdate dumps core on NetBSD/i386 4.x

[Mark Andrews]

In message <p05200f72c5d61071b990@[130.102.20.138]>, Ray Phillips writes:
> >	You need to call gdb correctly.
> >
> >	gdb /usr/local/bin/nsupdate nsupdate.core
> 
> Thanks Mark.
> 
> Sorry, I (obviously) don't have much of a clue about using gdb.

	Looks like you have hit this bug.

2547.   [bug]           openssl_link.c:mem_realloc() could reference an
                        out-of-range area of the source buffer.  New public
                        function isc_mem_reallocate() was introduced to address
                        this bug. [RT #19313]

	Mark

	
Index: bind9/CHANGES
diff -u bind9/CHANGES:1.2991 bind9/CHANGES:1.2992
--- bind9/CHANGES:1.2991	Fri Feb  6 12:33:17 2009
+++ bind9/CHANGES	Wed Feb 11 03:04:18 2009
@@ -1,3 +1,8 @@
+2547.	[bug]		openssl_link.c:mem_realloc() could reference an
+			out-of-range area of the source buffer.  New public
+			function isc_mem_reallocate() was introduced to address
+			this bug. [RT #19313]
+
 2546.	[func]		Add --enable-openssl-hash configure flag to use
 			OpenSSL (in place of internal routine) for hash
 			functions (MD5, SHA[12] and HMAC). [RT #18815]
Index: bind9/lib/dns/openssl_link.c
diff -u bind9/lib/dns/openssl_link.c:1.24 bind9/lib/dns/openssl_link.c:1.25
--- bind9/lib/dns/openssl_link.c:1.24	Sat Jan 17 23:47:42 2009
+++ bind9/lib/dns/openssl_link.c	Wed Feb 11 03:04:18 2009
@@ -148,18 +148,8 @@
 
 static void *
 mem_realloc(void *ptr, size_t size) {
-	void *p;
-
 	INSIST(dst__memory_pool != NULL);
-	p = NULL;
-	if (size > 0U) {
-		p = mem_alloc(size);
-		if (p != NULL && ptr != NULL)
-			memcpy(p, ptr, size);
-	}
-	if (ptr != NULL)
-		mem_free(ptr);
-	return (p);
+	return (isc_mem_reallocate(dst__memory_pool, ptr, size));
 }
 
 isc_result_t
Index: bind9/lib/isc/mem.c
diff -u bind9/lib/isc/mem.c:1.147 bind9/lib/isc/mem.c:1.148
--- bind9/lib/isc/mem.c:1.147	Thu Jan 22 23:47:54 2009
+++ bind9/lib/isc/mem.c	Wed Feb 11 03:04:18 2009
@@ -1365,6 +1365,40 @@
 	return (si);
 }
 
+void *
+isc__mem_reallocate(isc_mem_t *ctx, void *ptr, size_t size FLARG) {
+	void *new_ptr = NULL;
+	size_t oldsize, copysize;
+
+	REQUIRE(VALID_CONTEXT(ctx));
+
+	/*
+	 * This function emulates the realloc(3) standard library function:
+	 * - if size > 0, allocate new memory; and if ptr is non NULL, copy
+	 *   as much of the old contents to the new buffer and free the old one.
+	 *   Note that when allocation fails the original pointer is intact;
+	 *   the caller must free it.
+	 * - if size is 0 and ptr is non NULL, simply free the given ptr.
+	 * - this function returns:
+	 *     pointer to the newly allocated memory, or
+	 *     NULL if allocation fails or doesn't happen.
+	 */
+	if (size > 0U) {
+		new_ptr = isc__mem_allocate(ctx, size FLARG_PASS);
+		if (new_ptr != NULL && ptr != NULL) {
+			oldsize = (((size_info *)ptr)[-1]).u.size;
+			INSIST(oldsize >= ALIGNMENT_SIZE);
+			oldsize -= ALIGNMENT_SIZE;
+			copysize = oldsize > size ? size : oldsize;
+			memcpy(new_ptr, ptr, copysize);
+			isc__mem_free(ctx, ptr FLARG_PASS);
+		}
+	} else if (ptr != NULL)
+		isc__mem_free(ctx, ptr FLARG_PASS);
+
+	return (new_ptr);
+}
+
 void
 isc__mem_free(isc_mem_t *ctx, void *ptr FLARG) {
 	size_info *si;
Index: bind9/lib/isc/include/isc/mem.h
diff -u bind9/lib/isc/include/isc/mem.h:1.80 bind9/lib/isc/include/isc/mem.h:1.81
--- bind9/lib/isc/include/isc/mem.h:1.80	Sat Jan 17 23:47:43 2009
+++ bind9/lib/isc/include/isc/mem.h	Wed Feb 11 03:04:18 2009
@@ -154,6 +154,7 @@
 
 #define isc_mem_get(c, s)	isc__mem_get((c), (s) _ISC_MEM_FILELINE)
 #define isc_mem_allocate(c, s)	isc__mem_allocate((c), (s) _ISC_MEM_FILELINE)
+#define isc_mem_reallocate(c, p, s) isc__mem_reallocate((c), (p), (s) _ISC_MEM_FILELINE)
 #define isc_mem_strdup(c, p)	isc__mem_strdup((c), (p) _ISC_MEM_FILELINE)
 #define isc_mempool_get(c)	isc__mempool_get((c) _ISC_MEM_FILELINE)
 
@@ -612,6 +613,8 @@
 isc__mem_put(isc_mem_t *, void *, size_t _ISC_MEM_FLARG);
 void *
 isc__mem_allocate(isc_mem_t *, size_t _ISC_MEM_FLARG);
+void *
+isc__mem_reallocate(isc_mem_t *, void *, size_t _ISC_MEM_FLARG);
 void
 isc__mem_free(isc_mem_t *, void * _ISC_MEM_FLARG);
 char *
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org