From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fhigh-b1-smtp.messagingengine.com (fhigh-b1-smtp.messagingengine.com [202.12.124.152]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5301F31B833; Mon, 6 Apr 2026 05:58:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.152 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775455107; cv=none; b=G02OPdP7WofIsjnfOthrDjdbwmBDTFQs/prC2yD2RM6eO7+lOYY9p+XXNY19nZ+N5lkKpiCrrjIl3Xge4pt/PRoe1pnax+HioADLzuKcl8KqbrknMS7Et0Br4Ic6IbUEmOIaHE1AEuVL/PiUIMK8xQQPryGKfTfgyUWlFGnJDE8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775455107; c=relaxed/simple; bh=Z2syZCRUxcfZ3182R/tZWk6f6dHkZgsx5oU/jhr2dLk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rYxQC0hve2TOpnIJkf96VLlDH/qtxmGJvbAFzMy00MmO1x7c+VRNsRf1Gr3HGBKUWd/7psRFxXkZbqu4HTv5Z38TiCwPKga6rsHQbs+ITlkt8NqP0TYV2+MmdNmHyZXHNOhEKv3MwqLmBZ5nTVojQSza0IQvOmu4DA8gW1uyF9w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tyhicks.com; spf=pass smtp.mailfrom=tyhicks.com; dkim=pass (2048-bit key) header.d=tyhicks.com header.i=@tyhicks.com header.b=yJNP7tGe; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=Lt3g7lhI; arc=none smtp.client-ip=202.12.124.152 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tyhicks.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tyhicks.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tyhicks.com header.i=@tyhicks.com header.b="yJNP7tGe"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="Lt3g7lhI" Received: from phl-compute-05.internal (phl-compute-05.internal [10.202.2.45]) by mailfhigh.stl.internal (Postfix) with ESMTP id A6F937A0124; Mon, 6 Apr 2026 01:58:25 -0400 (EDT) Received: from phl-frontend-04 ([10.202.2.163]) by phl-compute-05.internal (MEProxy); Mon, 06 Apr 2026 01:58:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tyhicks.com; h= cc:cc:content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:subject :subject:to:to; s=fm1; t=1775455105; x=1775541505; bh=M3f8YxGaxD sLnBE52bn4EKhAHDhUWCPhwFmKNpqk3aM=; b=yJNP7tGe4QqtutR2sH8OjEOSli mUBMEfGKCs2UzbWNtW3m2LTHsvu6s8UxfsjKqnBTqPF/imZ89QnyfMyxS0/VgbUz vaJg1BuyDZFyUxCsicOwOZ7upNTZ+FExxNw1jWdd5xfag0uDCOAvJUB6Vj9RhCM3 v7jZQ1bmdDJQLceMa0EOEGSQVqjUaksROwcqz9UtJLnG3uJt2HZj14V8zHH4EcWd bGZKd5JsAiPsk1DD49zVa/0rMmqpTRQDqLF7+ztqZSlq3/rfwS8iySLd2oR6jTc6 NECMNIYSao/Zhsu4w6cKqUXIvOEYfnYUQLKMxotAfdHo4IT+vJqZdwCxlGmg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:subject:subject:to :to:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t= 1775455105; x=1775541505; bh=M3f8YxGaxDsLnBE52bn4EKhAHDhUWCPhwFm KNpqk3aM=; b=Lt3g7lhIajjkhWtVqdLjSWgmUggdly0wtR/9osFfhmbrLQlkR5V 7Rt4zoyUsw50FA+hOEAKsLfF4EDweFvWn+wLysbgBTQAL3Ms/ZfCd/cAbbPivaQL ZZE4yn8VNQS66GPv75p61XVEDZOtPBZ5QGrT4reT+Hr7HduBZS+CREP2YNIFziuJ wxqlnGn/T+9E9iRxltuAcOWvAUHniBl7ef2yoSto8tIvB1oStKu/ZqU70qVPSTew NM5eNpdmWaexXIe4EaL9286jSVPihSuSSFnmJxioz0u3AvYwtvtotgJeGkW5iEQg 50eCsHJ84eR52XhCxVASuWTqh4fkyZxrnsA== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefhedrtddtgdduieeltdcutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpuffrtefokffrpgfnqfghnecuuegr ihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjug hrpeffhffvvefukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpefvhihlvghrucfj ihgtkhhsuceotghouggvsehthihhihgtkhhsrdgtohhmqeenucggtffrrghtthgvrhhnpe dvhedvtddthfefhfdtgfelheefgefgudejueevkeduveekvdegjedttdefgfelieenucev lhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegtohguvgesth ihhhhitghkshdrtghomhdpnhgspghrtghpthhtohepfedpmhhouggvpehsmhhtphhouhht pdhrtghpthhtohephhgthheslhhsthdruggvpdhrtghpthhtohepvggtrhihphhtfhhsse hvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqfhhsuggvvhgv lhesvhhgvghrrdhkvghrnhgvlhdrohhrgh X-ME-Proxy: Feedback-ID: i78e14604:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 6 Apr 2026 01:58:25 -0400 (EDT) Date: Mon, 6 Apr 2026 00:58:23 -0500 From: Tyler Hicks To: Christoph Hellwig Cc: ecryptfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 5/7] ecryptfs: sanitize struct iattr handling in truncate_upper Message-ID: References: <20260331153752.4049454-1-hch@lst.de> <20260331153752.4049454-6-hch@lst.de> Precedence: bulk X-Mailing-List: ecryptfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260331153752.4049454-6-hch@lst.de> On 2026-03-31 17:37:26, Christoph Hellwig wrote: > Currently the two callers of truncate_upper handle passing information > very differently. ecryptfs_truncate passes a zeroed lower_ia and expects > truncate_upper to fill it in from the upper ia created just for that, > while ecryptfs_setattr passes a fully initialized lower_ia copied from > the upper one. > > Switch to only passing a lower ia which must have ia_size set to the > expected lower size, which cleans up the logic in truncate_upper and > ecryptfs_truncate. This one isn't making sense to me. It is shoving the upper inode size into the lower_ia->ia_size, which are two different values for encrypted files. I find that it makes truncate_upper() more confusing to read. I'm wondering if the following function signature would make more sense so that we can make better sense of which inode size we're talking about: static int truncate_upper(struct dentry *dentry, size_t upper_size, struct iattr *lower_ia) Tyler > > Signed-off-by: Christoph Hellwig > --- > fs/ecryptfs/inode.c | 39 ++++++++++++++++++--------------------- > 1 file changed, 18 insertions(+), 21 deletions(-) > > diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c > index 7a3da72eb3c6..a7dc25fae8ee 100644 > --- a/fs/ecryptfs/inode.c > +++ b/fs/ecryptfs/inode.c > @@ -709,7 +709,6 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat, > /** > * truncate_upper > * @dentry: The ecryptfs layer dentry > - * @ia: Address of the ecryptfs inode's attributes > * @lower_ia: Address of the lower inode's attributes > * > * Function to handle truncations modifying the size of the file. Note > @@ -722,8 +721,7 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat, > * > * Returns zero on success; non-zero otherwise > */ > -static int truncate_upper(struct dentry *dentry, struct iattr *ia, > - struct iattr *lower_ia) > +static int truncate_upper(struct dentry *dentry, struct iattr *lower_ia) > { > struct inode *inode = d_inode(dentry); > struct ecryptfs_crypt_stat *crypt_stat; > @@ -733,7 +731,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, > size_t num_zeros; > int rc; > > - if (unlikely((ia->ia_size == i_size))) { > + if (unlikely(lower_ia->ia_size == i_size)) { > lower_ia->ia_valid &= ~ATTR_SIZE; > return 0; > } > @@ -742,7 +740,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, > if (rc) > return rc; > > - if (ia->ia_size > i_size) { > + if (lower_ia->ia_size > i_size) { > char zero[] = { 0x00 }; > > /* > @@ -751,16 +749,14 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, > * intermediate portion of the previous end of the file and the > * new and of the file. > */ > - rc = ecryptfs_write(inode, zero, ia->ia_size - 1, 1); > + rc = ecryptfs_write(inode, zero, lower_ia->ia_size - 1, 1); > lower_ia->ia_valid &= ~ATTR_SIZE; > goto out; > } > > crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat; > if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { > - truncate_setsize(inode, ia->ia_size); > - lower_ia->ia_size = ia->ia_size; > - lower_ia->ia_valid |= ATTR_SIZE; > + truncate_setsize(inode, lower_ia->ia_size); > goto out; > } > > @@ -769,17 +765,17 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, > * ia->ia_size is located. Fill in the end of that page from > * (ia->ia_size & ~PAGE_MASK) to PAGE_SIZE with zeros. > */ > - num_zeros = PAGE_SIZE - (ia->ia_size & ~PAGE_MASK); > + num_zeros = PAGE_SIZE - (lower_ia->ia_size & ~PAGE_MASK); > if (num_zeros) { > rc = ecryptfs_write(inode, page_address(ZERO_PAGE(0)), > - ia->ia_size, num_zeros); > + lower_ia->ia_size, num_zeros); > if (rc) { > pr_err("Error attempting to zero out the remainder of the end page on reducing truncate; rc = [%d]\n", > rc); > goto out; > } > } > - truncate_setsize(inode, ia->ia_size); > + truncate_setsize(inode, lower_ia->ia_size); > rc = ecryptfs_write_inode_size_to_metadata(inode); > if (rc) { > pr_err("Problem with ecryptfs_write_inode_size_to_metadata; rc = [%d]\n", > @@ -794,13 +790,12 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, > lower_size_before_truncate = > upper_size_to_lower_size(crypt_stat, i_size); > lower_size_after_truncate = > - upper_size_to_lower_size(crypt_stat, ia->ia_size); > - if (lower_size_after_truncate < lower_size_before_truncate) { > + upper_size_to_lower_size(crypt_stat, lower_ia->ia_size); > + if (lower_size_after_truncate < lower_size_before_truncate) > lower_ia->ia_size = lower_size_after_truncate; > - lower_ia->ia_valid |= ATTR_SIZE; > - } else { > + else > lower_ia->ia_valid &= ~ATTR_SIZE; > - } > + > out: > ecryptfs_put_lower_file(inode); > return rc; > @@ -840,15 +835,17 @@ static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset) > */ > int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) > { > - struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length }; > - struct iattr lower_ia = { .ia_valid = 0 }; > + struct iattr lower_ia = { > + .ia_valid = ATTR_SIZE, > + .ia_size = new_length, > + }; > int rc; > > rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length); > if (rc) > return rc; > > - rc = truncate_upper(dentry, &ia, &lower_ia); > + rc = truncate_upper(dentry, &lower_ia); > if (!rc && lower_ia.ia_valid & ATTR_SIZE) { > struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); > > @@ -943,7 +940,7 @@ static int ecryptfs_setattr(struct mnt_idmap *idmap, > if (rc) > goto out; > > - rc = truncate_upper(dentry, ia, &lower_ia); > + rc = truncate_upper(dentry, &lower_ia); > if (rc < 0) > goto out; > } > -- > 2.47.3 >