Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753595AbdCHRQC (ORCPT ); Wed, 8 Mar 2017 12:16:02 -0500 Received: from mail-wm0-f47.google.com ([74.125.82.47]:32913 "EHLO mail-wm0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751975AbdCHRQA (ORCPT ); Wed, 8 Mar 2017 12:16:00 -0500 From: Alexander Potapenko To: dvyukov@google.com, kcc@google.com, edumazet@google.com, davem@davemloft.net Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v2] net: initialize msg.msg_flags in recvfrom Date: Wed, 8 Mar 2017 18:08:16 +0100 Message-Id: <20170308170816.8533-1-glider@google.com> X-Mailer: git-send-email 2.12.0.246.ga2ecc84866-goog Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 920 Lines: 27 KMSAN reports a use of uninitialized memory in put_cmsg() because msg.msg_flags in recvfrom haven't been initialized properly. The flag values don't affect the result on this path, but it's still a good idea to initialize them explicitly. Signed-off-by: Alexander Potapenko --- Changes since v1: - removed KMSAN report and reproducer from the description --- net/socket.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/socket.c b/net/socket.c index 2c1e8677ff2d..e0757e648c0c 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1731,6 +1731,7 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size, /* We assume all kernel code knows the size of sockaddr_storage */ msg.msg_namelen = 0; msg.msg_iocb = NULL; + msg.msg_flags = 0; if (sock->file->f_flags & O_NONBLOCK) flags |= MSG_DONTWAIT; err = sock_recvmsg(sock, &msg, flags); -- 2.12.0.246.ga2ecc84866-goog