about summary refs log tree commit diff
path: root/sysdeps/posix/getaddrinfo.c
diff options
context:
space:
mode:
authorSiddhesh Poyarekar <siddhesh@redhat.com>2013-10-25 10:22:12 +0530
committerSiddhesh Poyarekar <siddhesh@redhat.com>2013-10-25 10:22:12 +0530
commit7cbcdb3699584db8913ca90f705d6337633ee10f (patch)
treea260a3b6afb62ce20602c0672b6ea040e4db2c8c /sysdeps/posix/getaddrinfo.c
parent894f3f1049135dcbeaab8f18690973663ef3147c (diff)
downloadglibc-7cbcdb3699584db8913ca90f705d6337633ee10f.tar.gz
glibc-7cbcdb3699584db8913ca90f705d6337633ee10f.tar.xz
glibc-7cbcdb3699584db8913ca90f705d6337633ee10f.zip
Fix stack overflow due to large AF_INET6 requests
Resolves #16072 (CVE-2013-4458).

This patch fixes another stack overflow in getaddrinfo when it is
called with AF_INET6.  The AF_UNSPEC case was fixed as CVE-2013-1914,
but the AF_INET6 case went undetected back then.
Diffstat (limited to 'sysdeps/posix/getaddrinfo.c')
-rw-r--r--sysdeps/posix/getaddrinfo.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c
index e6ce4cfd63..8ff74b4965 100644
--- a/sysdeps/posix/getaddrinfo.c
+++ b/sysdeps/posix/getaddrinfo.c
@@ -197,7 +197,22 @@ gaih_inet_serv (const char *servicename, const struct gaih_typeproto *tp,
 				&rc, &herrno, NULL, &localcanon));	      \
     if (rc != ERANGE || herrno != NETDB_INTERNAL)			      \
       break;								      \
-    tmpbuf = extend_alloca (tmpbuf, tmpbuflen, 2 * tmpbuflen);		      \
+    if (!malloc_tmpbuf && __libc_use_alloca (alloca_used + 2 * tmpbuflen))    \
+      tmpbuf = extend_alloca_account (tmpbuf, tmpbuflen, 2 * tmpbuflen,	      \
+				      alloca_used);			      \
+    else								      \
+      {									      \
+	char *newp = realloc (malloc_tmpbuf ? tmpbuf : NULL,		      \
+			      2 * tmpbuflen);				      \
+	if (newp == NULL)						      \
+	  {								      \
+	    result = -EAI_MEMORY;					      \
+	    goto free_and_return;					      \
+	  }								      \
+	tmpbuf = newp;							      \
+	malloc_tmpbuf = true;						      \
+	tmpbuflen = 2 * tmpbuflen;					      \
+      }									      \
   }									      \
   if (status == NSS_STATUS_SUCCESS && rc == 0)				      \
     h = &th;								      \
@@ -209,7 +224,8 @@ gaih_inet_serv (const char *servicename, const struct gaih_typeproto *tp,
 	{								      \
 	  __set_h_errno (herrno);					      \
 	  _res.options |= old_res_options & RES_USE_INET6;		      \
-	  return -EAI_SYSTEM;						      \
+	  result = -EAI_SYSTEM;						      \
+	  goto free_and_return;						      \
 	}								      \
       if (herrno == TRY_AGAIN)						      \
 	no_data = EAI_AGAIN;						      \