upstream commit

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

Upstream-ID: 822d664d6a5a1d10eccb23acdd53578a679d5065

15 files changed, 58 insertions, 59 deletions

diff --git a/auth2-pubkey.c b/auth2-pubkey.c
index 7a6280f8d..271dbaf65 100644
--- a/auth2-pubkey.c
+++ b/auth2-pubkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-pubkey.c,v 1.65 2017/05/30 14:29:59 markus Exp $ */
+/* $OpenBSD: auth2-pubkey.c,v 1.66 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -1156,9 +1156,10 @@ auth2_record_userkey(Authctxt *authctxt, struct sshkey *key)
 	struct sshkey **tmp;
 
 	if (authctxt->nprev_userkeys >= INT_MAX ||
-	    (tmp = reallocarray(authctxt->prev_userkeys,
-	    authctxt->nprev_userkeys + 1, sizeof(*tmp))) == NULL)
-		fatal("%s: reallocarray failed", __func__);
+	    (tmp = recallocarray(authctxt->prev_userkeys,
+	    authctxt->nprev_userkeys, authctxt->nprev_userkeys + 1,
+	    sizeof(*tmp))) == NULL)
+		fatal("%s: recallocarray failed", __func__);
 	authctxt->prev_userkeys = tmp;
 	authctxt->prev_userkeys[authctxt->nprev_userkeys] = key;
 	authctxt->nprev_userkeys++;
diff --git a/authfile.c b/authfile.c
index af4190eeb..3481e0b04 100644
--- a/authfile.c
+++ b/authfile.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfile.c,v 1.125 2017/05/30 08:49:32 markus Exp $ */
+/* $OpenBSD: authfile.c,v 1.126 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * Copyright (c) 2000, 2013 Markus Friedl.  All rights reserved.
  *
@@ -100,25 +100,13 @@ sshkey_load_file(int fd, struct sshbuf *blob)
 	u_char buf[1024];
 	size_t len;
 	struct stat st;
-	int r, dontmax = 0;
+	int r;
 
 	if (fstat(fd, &st) < 0)
 		return SSH_ERR_SYSTEM_ERROR;
 	if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
 	    st.st_size > MAX_KEY_FILE_SIZE)
 		return SSH_ERR_INVALID_FORMAT;
-	/*
-	 * Pre-allocate the buffer used for the key contents and clamp its
-	 * maximum size. This ensures that key contents are never leaked via
-	 * implicit realloc() in the sshbuf code.
-	 */
-	if ((st.st_mode & S_IFREG) == 0 || st.st_size <= 0) {
-		st.st_size = 64*1024; /* 64k ought to be enough for anybody. :) */
-		dontmax = 1;
-	}
-	if ((r = sshbuf_allocate(blob, st.st_size)) != 0 ||
-	    (dontmax && (r = sshbuf_set_max_size(blob, st.st_size)) != 0))
-		return r;
 	for (;;) {
 		if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) {
 			if (errno == EPIPE)
diff --git a/bitmap.c b/bitmap.c
index 3d7aa1379..71f87ec54 100644
--- a/bitmap.c
+++ b/bitmap.c
@@ -87,7 +87,7 @@ reserve(struct bitmap *b, u_int n)
 		return -1; /* invalid */
 	nlen = (n / BITMAP_BITS) + 1;
 	if (b->len < nlen) {
-		if ((tmp = reallocarray(b->d, nlen, BITMAP_BYTES)) == NULL)
+		if ((tmp = recallocarray(b->d, b->len, nlen, BITMAP_BYTES)) == NULL)
 			return -1;
 		b->d = tmp;
 		memset(b->d + b->len, 0, (nlen - b->len) * BITMAP_BYTES);
diff --git a/clientloop.c b/clientloop.c
index 33d6fa908..612838376 100644
--- a/clientloop.c
+++ b/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.298 2017/05/31 07:00:13 markus Exp $ */
+/* $OpenBSD: clientloop.c,v 1.299 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1812,9 +1812,9 @@ hostkeys_find(struct hostkey_foreach_line *l, void *_ctx)
 	/* This line contained a key that not offered by the server */
 	debug3("%s: deprecated %s key at %s:%ld", __func__,
 	    sshkey_ssh_name(l->key), l->path, l->linenum);
-	if ((tmp = reallocarray(ctx->old_keys, ctx->nold + 1,
+	if ((tmp = recallocarray(ctx->old_keys, ctx->nold, ctx->nold + 1,
 	    sizeof(*ctx->old_keys))) == NULL)
-		fatal("%s: reallocarray failed nold = %zu",
+		fatal("%s: recallocarray failed nold = %zu",
 		    __func__, ctx->nold);
 	ctx->old_keys = tmp;
 	ctx->old_keys[ctx->nold++] = l->key;
@@ -2046,9 +2046,9 @@ client_input_hostkeys(void)
 			}
 		}
 		/* Key is good, record it */
-		if ((tmp = reallocarray(ctx->keys, ctx->nkeys + 1,
+		if ((tmp = recallocarray(ctx->keys, ctx->nkeys, ctx->nkeys + 1,
 		    sizeof(*ctx->keys))) == NULL)
-			fatal("%s: reallocarray failed nkeys = %zu",
+			fatal("%s: recallocarray failed nkeys = %zu",
 			    __func__, ctx->nkeys);
 		ctx->keys = tmp;
 		ctx->keys[ctx->nkeys++] = key;
diff --git a/hostfile.c b/hostfile.c
index 1804cff99..12f174ff9 100644
--- a/hostfile.c
+++ b/hostfile.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: hostfile.c,v 1.70 2017/04/30 23:18:44 djm Exp $ */
+/* $OpenBSD: hostfile.c,v 1.71 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -251,7 +251,7 @@ record_hostkey(struct hostkey_foreach_line *l, void *_ctx)
 	    l->marker == MRK_NONE ? "" :
 	    (l->marker == MRK_CA ? "ca " : "revoked "),
 	    sshkey_type(l->key), l->path, l->linenum);
-	if ((tmp = reallocarray(hostkeys->entries,
+	if ((tmp = recallocarray(hostkeys->entries, hostkeys->num_entries,
 	    hostkeys->num_entries + 1, sizeof(*hostkeys->entries))) == NULL)
 		return SSH_ERR_ALLOC_FAIL;
 	hostkeys->entries = tmp;
diff --git a/krl.c b/krl.c
index 3f28178b7..086fc20e5 100644
--- a/krl.c
+++ b/krl.c
@@ -14,7 +14,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $OpenBSD: krl.c,v 1.39 2017/03/10 07:18:32 dtucker Exp $ */
+/* $OpenBSD: krl.c,v 1.40 2017/05/31 09:15:42 deraadt Exp $ */
 
 #include "includes.h"
 
@@ -1026,7 +1026,7 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp,
 			}
 		}
 		/* Record keys used to sign the KRL */
-		tmp_ca_used = reallocarray(ca_used, nca_used + 1,
+		tmp_ca_used = recallocarray(ca_used, nca_used, nca_used + 1,
 		    sizeof(*ca_used));
 		if (tmp_ca_used == NULL) {
 			r = SSH_ERR_ALLOC_FAIL;
diff --git a/misc.c b/misc.c
index cfd32729a..af24fa5c4 100644
--- a/misc.c
+++ b/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.109 2017/03/14 00:55:37 dtucker Exp $ */
+/* $OpenBSD: misc.c,v 1.110 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -539,7 +539,7 @@ addargs(arglist *args, char *fmt, ...)
 	} else if (args->num+2 >= nalloc)
 		nalloc *= 2;
 
-	args->list = xreallocarray(args->list, nalloc, sizeof(char *));
+	args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *));
 	args->nalloc = nalloc;
 	args->list[args->num++] = cp;
 	args->list[args->num] = NULL;
diff --git a/scp.c b/scp.c
index f9f48e075..a533eb097 100644
--- a/scp.c
+++ b/scp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: scp.c,v 1.191 2017/05/02 08:06:33 jmc Exp $ */
+/* $OpenBSD: scp.c,v 1.192 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * scp - secure remote copy.  This is basically patched BSD rcp which
  * uses ssh to do the data transfer (instead of using rcmd).
@@ -1368,11 +1368,7 @@ allocbuf(BUF *bp, int fd, int blksize)
 #endif /* HAVE_STRUCT_STAT_ST_BLKSIZE */
 	if (bp->cnt >= size)
 		return (bp);
-	if (bp->buf == NULL)
-		bp->buf = xmalloc(size);
-	else
-		bp->buf = xreallocarray(bp->buf, 1, size);
-	memset(bp->buf, 0, size);
+	bp->buf = xrecallocarray(bp->buf, bp->cnt, size, 1);
 	bp->cnt = size;
 	return (bp);
 }
diff --git a/session.c b/session.c
index cbd27c689..4ef48ecd6 100644
--- a/session.c
+++ b/session.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: session.c,v 1.287 2017/05/31 08:09:45 markus Exp $ */
+/* $OpenBSD: session.c,v 1.288 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
@@ -1711,8 +1711,8 @@ session_new(void)
 			return NULL;
 		debug2("%s: allocate (allocated %d max %d)",
 		    __func__, sessions_nalloc, options.max_sessions);
-		tmp = xreallocarray(sessions, sessions_nalloc + 1,
-		    sizeof(*sessions));
+		tmp = xrecallocarray(sessions, sessions_nalloc,
+		    sessions_nalloc + 1, sizeof(*sessions));
 		if (tmp == NULL) {
 			error("%s: cannot allocate %d sessions",
 			    __func__, sessions_nalloc + 1);
@@ -2036,8 +2036,8 @@ session_env_req(Session *s)
 	for (i = 0; i < options.num_accept_env; i++) {
 		if (match_pattern(name, options.accept_env[i])) {
 			debug2("Setting env %d: %s=%s", s->num_env, name, val);
-			s->env = xreallocarray(s->env, s->num_env + 1,
-			    sizeof(*s->env));
+			s->env = xrecallocarray(s->env, s->num_env,
+			    s->num_env + 1, sizeof(*s->env));
 			s->env[s->num_env].name = name;
 			s->env[s->num_env].val = val;
 			s->num_env++;
diff --git a/ssh-pkcs11.c b/ssh-pkcs11.c
index ea97508f1..b37491c5d 100644
--- a/ssh-pkcs11.c
+++ b/ssh-pkcs11.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-pkcs11.c,v 1.24 2017/05/30 14:15:17 markus Exp $ */
+/* $OpenBSD: ssh-pkcs11.c,v 1.25 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * Copyright (c) 2010 Markus Friedl.  All rights reserved.
  *
@@ -546,8 +546,8 @@ pkcs11_fetch_keys_filter(struct pkcs11_provider *p, CK_ULONG slotidx,
 				sshkey_free(key);
 			} else {
 				/* expand key array and add key */
-				*keysp = xreallocarray(*keysp, *nkeys + 1,
-				    sizeof(struct sshkey *));
+				*keysp = xrecallocarray(*keysp, *nkeys,
+				    *nkeys + 1, sizeof(struct sshkey *));
 				(*keysp)[*nkeys] = key;
 				*nkeys = *nkeys + 1;
 				debug("have %d keys", *nkeys);
diff --git a/sshbuf.c b/sshbuf.c
index 652c99a21..b7a90b5c2 100644
--- a/sshbuf.c
+++ b/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
  *
@@ -193,15 +193,16 @@ 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
@@ -253,9 +254,8 @@ 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;
@@ -344,7 +344,7 @@ 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;
 	}
diff --git a/sshkey.c b/sshkey.c
index f9518bd77..9a3f0be58 100644
--- a/sshkey.c
+++ b/sshkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshkey.c,v 1.50 2017/05/08 06:11:06 djm Exp $ */
+/* $OpenBSD: sshkey.c,v 1.51 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
@@ -1764,8 +1764,9 @@ cert_parse(struct sshbuf *b, struct sshkey *key, struct sshbuf *certbuf)
 			goto out;
 		}
 		oprincipals = key->cert->principals;
-		key->cert->principals = reallocarray(key->cert->principals,
-		    key->cert->nprincipals + 1, sizeof(*key->cert->principals));
+		key->cert->principals = recallocarray(key->cert->principals,
+		    key->cert->nprincipals, key->cert->nprincipals + 1,
+		    sizeof(*key->cert->principals));
 		if (key->cert->principals == NULL) {
 			free(principal);
 			key->cert->principals = oprincipals;
diff --git a/utf8.c b/utf8.c
index da5778138..bc131385f 100644
--- a/utf8.c
+++ b/utf8.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: utf8.c,v 1.6 2017/04/17 14:31:23 schwarze Exp $ */
+/* $OpenBSD: utf8.c,v 1.7 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -76,7 +76,7 @@ grow_dst(char **dst, size_t *sz, size_t maxsz, char **dp, size_t need)
 	tsz = *sz + 128;
 	if (tsz > maxsz)
 		tsz = maxsz;
-	if ((tp = realloc(*dst, tsz)) == NULL)
+	if ((tp = recallocarray(*dst, *sz, tsz, 1)) == NULL)
 		return -1;
 	*dp = tp + (*dp - *dst);
 	*dst = tp;
diff --git a/xmalloc.c b/xmalloc.c
index b58323677..5cc0310a4 100644
--- a/xmalloc.c
+++ b/xmalloc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: xmalloc.c,v 1.33 2016/02/15 09:47:49 dtucker Exp $ */
+/* $OpenBSD: xmalloc.c,v 1.34 2017/05/31 09:15:42 deraadt Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -77,6 +77,18 @@ xreallocarray(void *ptr, size_t nmemb, size_t size)
 	return new_ptr;
 }
 
+void *
+xrecallocarray(void *ptr, size_t onmemb, size_t nmemb, size_t size)
+{
+	void *new_ptr;
+
+	new_ptr = recallocarray(ptr, onmemb, nmemb, size);
+	if (new_ptr == NULL)
+		fatal("xrecallocarray: out of memory (%zu elements of %zu bytes)",
+		    nmemb, size);
+	return new_ptr;
+}
+
 char *
 xstrdup(const char *str)
 {
diff --git a/xmalloc.h b/xmalloc.h
index e49928932..cf38ddfa4 100644
--- a/xmalloc.h
+++ b/xmalloc.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: xmalloc.h,v 1.16 2016/02/15 09:47:49 dtucker Exp $ */
+/* $OpenBSD: xmalloc.h,v 1.17 2017/05/31 09:15:42 deraadt Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -20,6 +20,7 @@ void	 ssh_malloc_init(void);
 void	*xmalloc(size_t);
 void	*xcalloc(size_t, size_t);
 void	*xreallocarray(void *, size_t, size_t);
+void	*xrecallocarray(void *, size_t, size_t, size_t);
 char	*xstrdup(const char *);
 int	 xasprintf(char **, const char *, ...)
                 __attribute__((__format__ (printf, 2, 3)))