From patchwork Wed Mar 8 17:08:16 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Potapenko X-Patchwork-Id: 736669 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vdgDY29NLz9s8G for ; Thu, 9 Mar 2017 04:16:43 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="H/86BrwW"; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753815AbdCHRQZ (ORCPT ); Wed, 8 Mar 2017 12:16:25 -0500 Received: from mail-wm0-f48.google.com ([74.125.82.48]:37540 "EHLO mail-wm0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753721AbdCHRQY (ORCPT ); Wed, 8 Mar 2017 12:16:24 -0500 Received: by mail-wm0-f48.google.com with SMTP id n11so36494006wma.0 for ; Wed, 08 Mar 2017 09:16:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=NsItYAO5KWCFiEoWma5KcPopD0Duhsh1Val/+Hy4cb8=; b=H/86BrwWiYEEw8on9bj07FslJeF0SYy+O6hxOTNBL1D/1E6AVLYD28i9c8pAoTztAU UpNqLA24B2DM1gYCUPkcupKF10Rb5kh1s4v6PFBsDtdHp5WIHLFOUFQhRGZrjsYTSZkm PbeBEsptMVnhtYUc8o34x2wvkCHrOrJrWT4SIWcDshzmGQnmBtUMXEfnW/DWzQuzQtKb UCAmnj8qqL4fCTDNfT4+dPmz2hptx8R+o2stMS32xH0LmsAHPQKWAh5pRNrXvrEDRKcg fr8v9ktZ3btnqvAiIScBc2QoW28BwNE2QRLV9MqZRQH2Tgkw9QHxJdXU3/cRMpMPBWGs T2sg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=NsItYAO5KWCFiEoWma5KcPopD0Duhsh1Val/+Hy4cb8=; b=sp/8Ktu6GMBq9rO2esQaAyBxKLNwSsBhPiSz55QZqA14KZlsj2Ewu0UUw5weTg/lsK svdCX9MvTNollAamoxyNawKgdEWo7YR6nCrF+M4GtBwL0BF50F/Q+VDxLaGOgasnSFzh tZTyP1vvScBdNzG0ZcFt5ObSGC/T6eg3BgR7T5RvahWNqkocNPF/Qmm71h7e9PjRfs4/ /fQKxfMMh2k65W1WjCeRkGQEqg30Dy4Sdk5X+hH7hHFCFa0dYcbreh2XxZcs4CAmv/Oy yFIcoTBewMCQYrVlytp4g7COkARlbbaoz7gks2kruSTKwscVRvgfWv7nj2nTAfpbG9qJ vrhQ== X-Gm-Message-State: AMke39n9AJyC4pUeTREsr6Rny/GTbHEyzjbj69RCLgZMjaNh9pBsRP669TP2g30sLZ/WBOs9 X-Received: by 10.28.214.146 with SMTP id n140mr6490184wmg.58.1488992924217; Wed, 08 Mar 2017 09:08:44 -0800 (PST) Received: from glider0.muc.corp.google.com ([100.105.28.21]) by smtp.gmail.com with ESMTPSA id x25sm4925608wrx.4.2017.03.08.09.08.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 08 Mar 2017 09:08:43 -0800 (PST) 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: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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);