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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D27C0EB64DD for ; Thu, 3 Aug 2023 04:19:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231916AbjHCET2 (ORCPT ); Thu, 3 Aug 2023 00:19:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231958AbjHCETW (ORCPT ); Thu, 3 Aug 2023 00:19:22 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21C3930CF; Wed, 2 Aug 2023 21:19:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8A7B461BD4; Thu, 3 Aug 2023 04:19:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB582C433C9; Thu, 3 Aug 2023 04:19:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691036359; bh=VLs+scbvQ34KjbdAmierHUVPhapWUU91JYmANc8PqKA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=duU3ggpHzuB9R4XKQvBCRY2IFmay6LVBqGVtJKWp+VRJTgdIjz7s1nVGPrK1ihuZj 1n5YuwnRFusSr1JAuYeuCpN+6YjGMpSpLkcyIawIkJ7TGCFjkRGQ0UsCgQwKqb08fP ArWBoiC6mrP5MQhqo+Jv2NV0kx0RHc5jBPDKE6bOBs2ot+6nv96DGS6KHw66LoQNrD FH2Vk9LPwv71GB1ZrfPFJbOVezN8M/71Z0mk9Ew+S2j1K9A4oecuWtXa8C/yy3zrvj Dtu4gEVuXUDvyq41AjjmU2F0YOjq0qjWFmXMUumg6FWn6nRMyOUsuyY6KrOFnVDk9w CGcy7miwB3CmQ== Date: Wed, 2 Aug 2023 21:19:18 -0700 From: Eric Biggers To: =?iso-8859-1?Q?Lu=EDs?= Henriques Cc: Theodore Ts'o , Andreas Dilger , Daniel Rosenberg , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] ext4: fix memory leaks in ext4_fname_{setup_filename,prepare_lookup} Message-ID: <20230803041918.GA1218@sol.localdomain> References: <20230802094931.18215-1-lhenriques@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230802094931.18215-1-lhenriques@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 02, 2023 at 10:49:31AM +0100, Luís Henriques wrote: > If casefolding the filename fails, we'll be leaking fscrypt_buf name. fscrypt_buf => fscrypt_name > diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c > index e20ac0654b3f..3c05c7f3415b 100644 > --- a/fs/ext4/crypto.c > +++ b/fs/ext4/crypto.c > @@ -33,6 +33,8 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, > struct fscrypt_name name; > int err; > > err = fscrypt_setup_filename(dir, iname, lookup, &name); > if (err) > return err; > > ext4_fname_from_fscrypt_name(fname, &name); > > #if IS_ENABLED(CONFIG_UNICODE) > err = ext4_fname_setup_ci_filename(dir, iname, fname); > + if (err) > + fscrypt_free_filename(&name); > #endif > return err; > } > @@ -51,6 +53,8 @@ int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry, > struct fscrypt_name name; > int err; > > err = fscrypt_prepare_lookup(dir, dentry, &name); > if (err) > return err; > > ext4_fname_from_fscrypt_name(fname, &name); > > #if IS_ENABLED(CONFIG_UNICODE) > err = ext4_fname_setup_ci_filename(dir, &dentry->d_name, fname); > + if (err) > + fscrypt_free_filename(&name); > #endif > return err; > } This works, but it's a bit weird that the freeing happens on the original struct fscrypt_name after it has already been "moved" to the struct ext4_filename by ext4_fname_from_fscrypt_name(). That leaves a dangling pointer in the struct ext4_filename. Maybe you should call ext4_fname_free_filename() instead, even though it would do some unnecessary work? - Eric