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, URIBL_BLOCKED,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 28477C433E0 for ; Tue, 16 Jun 2020 14:48:39 +0000 (UTC) Received: from krantz.zx2c4.com (krantz.zx2c4.com [192.95.5.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A277C208B3 for ; Tue, 16 Jun 2020 14:48:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A277C208B3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=wireguard-bounces@lists.zx2c4.com Received: by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTP id ec8687c2; Tue, 16 Jun 2020 14:30:23 +0000 (UTC) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTPS id 613ac294 (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256:NO) for ; Tue, 16 Jun 2020 14:30:20 +0000 (UTC) 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> 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) X-BeenThere: wireguard@lists.zx2c4.com X-Mailman-Version: 2.1.30rc1 Precedence: list List-Id: Development discussion of WireGuard List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: dsterba@suse.cz Errors-To: wireguard-bounces@lists.zx2c4.com Sender: "WireGuard" 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.