upstream commit

apparently memcpy(x, NULL, 0) is undefined behaviour
 according to C99 (cf. sections 7.21.1 and 7.1.4), so check skip memcpy calls
 when length==0; ok markus@

1 files changed, 12 insertions, 7 deletions

diff --git a/sshbuf-getput-basic.c b/sshbuf-getput-basic.c
index 682b68d58..06d6cc492 100644
--- a/sshbuf-getput-basic.c
+++ b/sshbuf-getput-basic.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: sshbuf-getput-basic.c,v 1.2 2014/12/04 01:49:59 djm Exp $     */
+/*      $OpenBSD: sshbuf-getput-basic.c,v 1.3 2015/01/12 15:18:07 djm Exp $     */
 /*
  * Copyright (c) 2011 Damien Miller
  *
@@ -34,7 +34,7 @@ sshbuf_get(struct sshbuf *buf, void *v, size_t len)
 
         if ((r = sshbuf_consume(buf, len)) < 0)
                 return r;
-        if (v != NULL)
+        if (v != NULL && len != 0)
                 memcpy(v, p, len);
         return 0;
 }
@@ -109,7 +109,8 @@ sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp)
                         SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL"));
                         return SSH_ERR_ALLOC_FAIL;
                 }
-                memcpy(*valp, val, len);
+                if (len != 0)
+                        memcpy(*valp, val, len);
                 (*valp)[len] = '\0';
         }
         if (lenp != NULL)
@@ -200,7 +201,8 @@ sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp)
                         SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL"));
                         return SSH_ERR_ALLOC_FAIL;
                 }
-                memcpy(*valp, p, len);
+                if (len != 0)
+                        memcpy(*valp, p, len);
                 (*valp)[len] = '\0';
         }
         if (lenp != NULL)
@@ -236,7 +238,8 @@ sshbuf_put(struct sshbuf *buf, const void *v, size_t len)
 
         if ((r = sshbuf_reserve(buf, len, &p)) < 0)
                 return r;
-        memcpy(p, v, len);
+        if (len != 0)
+                memcpy(p, v, len);
         return 0;
 }
 
@@ -352,7 +355,8 @@ sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len)
         if ((r = sshbuf_reserve(buf, len + 4, &d)) < 0)
                 return r;
         POKE_U32(d, len);
-        memcpy(d + 4, v, len);
+        if (len != 0)
+                memcpy(d + 4, v, len);
         return 0;
 }
 
@@ -416,6 +420,7 @@ sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len)
         POKE_U32(d, len + prepend);
         if (prepend)
                 d[4] = 0;
-        memcpy(d + 4 + prepend, s, len);
+        if (len != 0)
+                memcpy(d + 4 + prepend, s, len);
         return 0;
 }