From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E89AC433E2 for ; Wed, 16 Sep 2020 06:15:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4387B206B7 for ; Wed, 16 Sep 2020 06:15:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kroah.com header.i=@kroah.com header.b="o9xA6zzn"; dkim=temperror (0-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="WhPubNBp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726169AbgIPGPu (ORCPT ); Wed, 16 Sep 2020 02:15:50 -0400 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:60017 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726093AbgIPGPt (ORCPT ); Wed, 16 Sep 2020 02:15:49 -0400 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 29E185C00F5; Wed, 16 Sep 2020 02:15:47 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Wed, 16 Sep 2020 02:15:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm1; bh=1FeN9RUCQkpP8rFk9zMjFMsMbdJ infBwncvpOPiw/sk=; b=o9xA6zznMel1d8/0CDVc5OYSNmEgxGIpOxDctBhzIWE lBXGqJlO8b1ePb9CbhfqZvwesuhmz4963su9cBPKtqYSKvbWKkl2m74i8jF2sjaW iPVY8/wr8pe/xjWMTUWMqyhIcJKiXb3qHDd8YewU3hSG71RUewTQwZioXnj2Jqpv Y3b9QII/aE65gZCXIkvMKndzPxJmzx+E8tE/zgi6oRpawR40ZpSy7ZkEwhwjzXdH oH7ZG2U/LmtOpxcwnX6ZZ23pMQt/LCSa//s49sMfHkxj70m3fCyNmUflSRVrkcAS TnuLYa5wfd+6LMybUxyne9/ZoGoVIbKbstmlYH6ssjQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=1FeN9R UCQkpP8rFk9zMjFMsMbdJinfBwncvpOPiw/sk=; b=WhPubNBp9ZHvAuf7n+yp1o M7JxwmAf3ckif65SowVRFr2gAcrF1V3GTmBHllx4mgZi+9WOI1YZPK6L8q09IxnS Tuk4AQiR/IQnRb6Y9wrEqqi5M/UnFCxaHNzFTa9lBHfBjZNQ3S3QBJSRqsWpLQoc gJyXhndSUBkbTmg7oKdPguP5m7G7gy3wCEJS/weSvcWleaI/5tmzVSoNoqyHFww0 esyQFoQFGCqYS3eYYAchKgi59Q6DFmMVlenBT212ZqOaFbJZbIhXhpbTubdjze8F i+GVWg2FTcCiIYXK6QB2rsTZjNmOqZ1m3WsNOokegaHZKtj66qtzW3dxRL4DU/Ng == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedujedrtddugdellecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpeffhffvuffkfhggtggujgesthdtredttddtvdenucfhrhhomhepifhrvghgucfm jfcuoehgrhgvgheskhhrohgrhhdrtghomheqnecuggftrfgrthhtvghrnhepjeehheetve eiffeutdfhleekkeefleevgfdufeehtdejgeejhfdvffeggfdugeefnecuffhomhgrihhn pehshiiikhgrlhhlvghrrdgrphhpshhpohhtrdgtohhmnecukfhppeekfedrkeeirdejge drieegnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhep ghhrvghgsehkrhhorghhrdgtohhm X-ME-Proxy: Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) by mail.messagingengine.com (Postfix) with ESMTPA id 5259E3064684; Wed, 16 Sep 2020 02:15:46 -0400 (EDT) Date: Wed, 16 Sep 2020 08:16:22 +0200 From: Greg KH To: Anant Thazhemadam Cc: linux-kernel@vger.kernel.org, Alexander Viro , linux-fsdevel@vger.kernel.org, syzbot+4191a44ad556eacc1a7a@syzkaller.appspotmail.com, linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [Linux-kernel-mentees] [PATCH] fs: fix KMSAN uninit-value bug by initializing nd in do_file_open_root Message-ID: <20200916061622.GA142621@kroah.com> References: <20200916052657.18683-1-anant.thazhemadam@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200916052657.18683-1-anant.thazhemadam@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Sep 16, 2020 at 10:56:56AM +0530, Anant Thazhemadam wrote: > The KMSAN bug report for the bug indicates that there exists; > Local variable ----nd@do_file_open_root created at: > do_file_open_root+0xa4/0xb40 fs/namei.c:3385 > do_file_open_root+0xa4/0xb40 fs/namei.c:3385 What does this "error" mean? > Initializing nd fixes this issue, and doesn't break anything else either > > Fixes: https://syzkaller.appspot.com/bug?extid=4191a44ad556eacc1a7a > Reported-by: syzbot+4191a44ad556eacc1a7a@syzkaller.appspotmail.com > Tested-by: syzbot+4191a44ad556eacc1a7a@syzkaller.appspotmail.com > Signed-off-by: Anant Thazhemadam > --- > fs/namei.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/namei.c b/fs/namei.c > index e99e2a9da0f7..b27382586209 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -3404,7 +3404,7 @@ struct file *do_filp_open(int dfd, struct filename *pathname, > struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt, > const char *name, const struct open_flags *op) > { > - struct nameidata nd; > + struct nameidata nd = {}; What exactly does setting this structure to all 0 fix here that is currently "broken"? confused, greg k-h