Bug 1141885 - Make readlink() fail instead of allowing it, for B2G content processes. r=kang

--HG--
extra : rebase_source : c9ceababcd741979058361e96161d575a70bd39f

security/sandbox/linux/SandboxFilter.cpp

@@ -207,8 +207,8 @@ SandboxFilterImplContent::Build() {
   Allow(SOCKETCALL(socketpair, SOCKETPAIR));
   Deny(EACCES, SOCKETCALL(socket, SOCKET));
   Allow(SYSCALL(open));
-  Allow(SYSCALL(readlink)); /* Workaround for bug 964455 */
-  Allow(SYSCALL(readlinkat)); /* Workaround for bug 964455 */
+  Deny(EINVAL, SYSCALL(readlink)); /* Workaround for bug 964455 */
+  Deny(EINVAL, SYSCALL(readlinkat)); /* Workaround for bug 964455 */
   Allow(SYSCALL(prctl));
   Allow(SYSCALL(access));
   Allow(SYSCALL(fsync));