Switch to recallocarray() for a few operations. Both growth and shrinkage

are handled safely, and there also is no need for preallocation dances.
Future changes in this area will be less error prone.
Review and one bug found by markus

1 files changed, 8 insertions, 8 deletions

diff --git a/usr.bin/ssh/sshbuf.c b/usr.bin/ssh/sshbuf.c
index e4a4f1e2f25..c97808005ec 100644
--- a/usr.bin/ssh/sshbuf.c
+++ b/usr.bin/ssh/sshbuf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sshbuf.c,v 1.9 2017/05/26 20:34:49 markus Exp $	*/
+/*	$OpenBSD: sshbuf.c,v 1.10 2017/05/31 09:15:42 deraadt Exp $	*/
 /*
  * Copyright (c) 2011 Damien Miller
  *
@@ -191,15 +191,16 @@ sshbuf_reset(struct sshbuf *buf)
 		buf->off = buf->size;
 		return;
 	}
-	if (sshbuf_check_sanity(buf) == 0)
-		explicit_bzero(buf->d, buf->alloc);
+	(void) sshbuf_check_sanity(buf);
 	buf->off = buf->size = 0;
 	if (buf->alloc != SSHBUF_SIZE_INIT) {
-		if ((d = realloc(buf->d, SSHBUF_SIZE_INIT)) != NULL) {
+		if ((d = recallocarray(buf->d, buf->alloc, SSHBUF_SIZE_INIT,
+		    1)) != NULL) {
 			buf->cd = buf->d = d;
 			buf->alloc = SSHBUF_SIZE_INIT;
 		}
-	}
+	} else
+		explicit_bzero(buf->d, SSHBUF_SIZE_INIT);
 }
 
 size_t
@@ -251,9 +252,8 @@ sshbuf_set_max_size(struct sshbuf *buf, size_t max_size)
 			rlen = ROUNDUP(buf->size, SSHBUF_SIZE_INC);
 		if (rlen > max_size)
 			rlen = max_size;
-		explicit_bzero(buf->d + buf->size, buf->alloc - buf->size);
 		SSHBUF_DBG(("new alloc = %zu", rlen));
-		if ((dp = realloc(buf->d, rlen)) == NULL)
+		if ((dp = recallocarray(buf->d, buf->alloc, rlen, 1)) == NULL)
 			return SSH_ERR_ALLOC_FAIL;
 		buf->cd = buf->d = dp;
 		buf->alloc = rlen;
@@ -342,7 +342,7 @@ sshbuf_allocate(struct sshbuf *buf, size_t len)
 	if (rlen > buf->max_size)
 		rlen = buf->alloc + need;
 	SSHBUF_DBG(("adjusted rlen %zu", rlen));
-	if ((dp = realloc(buf->d, rlen)) == NULL) {
+	if ((dp = recallocarray(buf->d, buf->alloc, rlen, 1)) == NULL) {
 		SSHBUF_DBG(("realloc fail"));
 		return SSH_ERR_ALLOC_FAIL;
 	}