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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 C89E8C433E1 for ; Tue, 16 Jun 2020 14:48:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEB7D208B3 for ; Tue, 16 Jun 2020 14:48:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729053AbgFPOsW (ORCPT ); Tue, 16 Jun 2020 10:48:22 -0400 Received: from mx2.suse.de ([195.135.220.15]:37776 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728501AbgFPOsV (ORCPT ); Tue, 16 Jun 2020 10:48:21 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 3F73AAAE8; Tue, 16 Jun 2020 14:48:18 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 50CC9DA7C3; Tue, 16 Jun 2020 16:48:04 +0200 (CEST) Date: Tue, 16 Jun 2020 16:48:04 +0200 From: David Sterba To: Waiman Long Cc: Andrew Morton , David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Linus Torvalds , Joe Perches , Matthew Wilcox , David Rientjes , Michal Hocko , Johannes Weiner , Dan Carpenter , David Sterba , "Jason A . Donenfeld" , linux-mm@kvack.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, linux-pm@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-amlogic@lists.infradead.org, linux-mediatek@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-ppp@vger.kernel.org, wireguard@lists.zx2c4.com, linux-wireless@vger.kernel.org, devel@driverdev.osuosl.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-fscrypt@vger.kernel.org, ecryptfs@vger.kernel.org, kasan-dev@googlegroups.com, linux-bluetooth@vger.kernel.org, linux-wpan@vger.kernel.org, linux-sctp@vger.kernel.org, linux-nfs@vger.kernel.org, tipc-discussion@lists.sourceforge.net, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org Subject: Re: [PATCH v4 3/3] btrfs: Use kfree() in btrfs_ioctl_get_subvol_info() Message-ID: <20200616144804.GD27795@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Waiman Long , Andrew Morton , David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Linus Torvalds , Joe Perches , Matthew Wilcox , David Rientjes , Michal Hocko , Johannes Weiner , Dan Carpenter , "Jason A . Donenfeld" , linux-mm@kvack.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, linux-pm@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-amlogic@lists.infradead.org, linux-mediatek@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-ppp@vger.kernel.org, wireguard@lists.zx2c4.com, linux-wireless@vger.kernel.org, devel@driverdev.osuosl.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-fscrypt@vger.kernel.org, ecryptfs@vger.kernel.org, kasan-dev@googlegroups.com, linux-bluetooth@vger.kernel.org, linux-wpan@vger.kernel.org, linux-sctp@vger.kernel.org, linux-nfs@vger.kernel.org, tipc-discussion@lists.sourceforge.net, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org References: <20200616015718.7812-1-longman@redhat.com> <20200616015718.7812-4-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200616015718.7812-4-longman@redhat.com> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org On Mon, Jun 15, 2020 at 09:57:18PM -0400, Waiman Long wrote: > In btrfs_ioctl_get_subvol_info(), there is a classic case where kzalloc() > was incorrectly paired with kzfree(). According to David Sterba, there > isn't any sensitive information in the subvol_info that needs to be > cleared before freeing. So kfree_sensitive() isn't really needed, > use kfree() instead. > > Reported-by: David Sterba > Signed-off-by: Waiman Long > --- > fs/btrfs/ioctl.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index f1dd9e4271e9..e8f7c5f00894 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -2692,7 +2692,7 @@ static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp) > btrfs_put_root(root); > out_free: > btrfs_free_path(path); > - kfree_sensitive(subvol_info); > + kfree(subvol_info); I would rather merge a patch doing to kzfree -> kfree instead of doing the middle step to switch it to kfree_sensitive. If it would help integration of your patchset I can push it to the next rc so there are no kzfree left in the btrfs code. Treewide change like that can take time so it would be one less problem to care about for you.