From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A48D54A2638; Tue, 6 Oct 2026 21:37:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791322665; cv=none; b=dJs/sBIsKAr34/MaIQMTv7tA7mvEnw9OAyRuact1Cjubpii1j9kZpY7/9smtxgyRCmy7oJ4VOPSVeeMOLnF9+YKpABso/vxG6QPmiZMQJxnLu6XAK19SF4Mtp15SEGE/c++plbnrkxibUBn0WVilFCnX0RYNzLfbT7B5mYtV69Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791322665; c=relaxed/simple; bh=uNBBti6gMimEQCmbYPP16rubNocP437bxzdNKV08N3Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pa9X8t/WeRmGCfG1y0iYvtopSIpB4dswRmivTrgaH/NIl+st4diaXBQsrMsJlANObEwhfdzYpDrwFhHyPkoHpgEvHsNj5iVvvbPxi8J4W//0ph3auMqb2z+XutymsB1sN/D0V9tvy83VM4PN67m3uV8bsS1SsK5dWSECtfCUMHY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jR0wmnkG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jR0wmnkG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F00031F0089C; Tue, 6 Oct 2026 21:37:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791322659; bh=dea5S6Lx22UU6xvhpnYR6J26hlvYIMb3bORP7o5WZhI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jR0wmnkGZWNSuZmFIav0i5ZvaN7JzCFMic3R5EUcSs4sk2b7pUz+FyN7RA6haeja/ 88/mWqS3XhUo3arV8AsAA04BsFQ2a/ifjtRUocgqQBsCVwROvEoBDkY9bOlXPYbQKj FN+1/HRe1yPJz2WFdNpho9SVKZdJ6kfeAYkyVg+Y63sLt/UTxTjh567qa6JOGnOYb0 CDXpnR3dj0uvNeOAREIW0Z2RzoC1RqSszLyORbccgcZWypPWeOgrzCXOYujht55ctv sUSH9hF2M78wyJG3EaPZveinYLVHpxiEDUsdefIAKB9lVktzMoevUD6qXm65nz081j c/bmMRS8SjKMQ== From: Eric Biggers To: stable@vger.kernel.org Cc: fsverity@lists.linux.dev, Christoph Hellwig , Jan Kara , "Darrick J. Wong" , Eric Biggers Subject: [PATCH 6.12 1/2] fs,fsverity: reject size changes on fsverity files in setattr_prepare Date: Tue, 6 Oct 2026 23:37:24 +0200 Message-ID: <20261006213725.47114-2-ebiggers@kernel.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261006213725.47114-1-ebiggers@kernel.org> References: <20261006213725.47114-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: fsverity@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Christoph Hellwig commit e9734653c523c744f03333ece6ae7a315187f05c upstream. Add the check to reject truncates of fsverity files directly to setattr_prepare instead of requiring the file system to handle it. Besides removing boilerplate code, this also fixes the complete lack of such check in btrfs. Fixes: 146054090b08 ("btrfs: initial fsverity support") Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: "Darrick J. Wong" Link: https://lore.kernel.org/r/20260128152630.627409-2-hch@lst.de Signed-off-by: Eric Biggers --- fs/attr.c | 12 +++++++++++- fs/ext4/inode.c | 4 ---- fs/f2fs/file.c | 4 ---- fs/verity/open.c | 8 -------- include/linux/fsverity.h | 25 ------------------------- 5 files changed, 11 insertions(+), 42 deletions(-) diff --git a/fs/attr.c b/fs/attr.c index c04d19b58f12..714f159d58ea 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -169,7 +169,17 @@ int setattr_prepare(struct mnt_idmap *idmap, struct dentry *dentry, * ATTR_FORCE. */ if (ia_valid & ATTR_SIZE) { - int error = inode_newsize_ok(inode, attr->ia_size); + int error; + + /* + * Verity files are immutable, so deny truncates. This isn't + * covered by the open-time check because sys_truncate() takes a + * path, not an open file. + */ + if (IS_ENABLED(CONFIG_FS_VERITY) && IS_VERITY(inode)) + return -EPERM; + + error = inode_newsize_ok(inode, attr->ia_size); if (error) return error; } diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index fa303effb18a..24b5925a7c7e 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5444,10 +5444,6 @@ int ext4_setattr(struct mnt_idmap *idmap, struct dentry *dentry, if (error) return error; - error = fsverity_prepare_setattr(dentry, attr); - if (error) - return error; - if (is_quota_modification(idmap, inode, attr)) { error = dquot_initialize(inode); if (error) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index a7ad5e02433c..b4bd73648a01 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1078,10 +1078,6 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry, if (err) return err; - err = fsverity_prepare_setattr(dentry, attr); - if (err) - return err; - if (unlikely(IS_IMMUTABLE(inode))) return -EPERM; diff --git a/fs/verity/open.c b/fs/verity/open.c index fdeb95eca3af..bd0497da5cea 100644 --- a/fs/verity/open.c +++ b/fs/verity/open.c @@ -392,14 +392,6 @@ int __fsverity_file_open(struct inode *inode, struct file *filp) } EXPORT_SYMBOL_GPL(__fsverity_file_open); -int __fsverity_prepare_setattr(struct dentry *dentry, struct iattr *attr) -{ - if (attr->ia_valid & ATTR_SIZE) - return -EPERM; - return 0; -} -EXPORT_SYMBOL_GPL(__fsverity_prepare_setattr); - void __fsverity_cleanup_inode(struct inode *inode) { fsverity_free_info(inode->i_verity_info); diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h index 1eb7eae580be..139a6f5c6217 100644 --- a/include/linux/fsverity.h +++ b/include/linux/fsverity.h @@ -149,7 +149,6 @@ int fsverity_get_digest(struct inode *inode, /* open.c */ int __fsverity_file_open(struct inode *inode, struct file *filp); -int __fsverity_prepare_setattr(struct dentry *dentry, struct iattr *attr); void __fsverity_cleanup_inode(struct inode *inode); /** @@ -214,12 +213,6 @@ static inline int __fsverity_file_open(struct inode *inode, struct file *filp) return -EOPNOTSUPP; } -static inline int __fsverity_prepare_setattr(struct dentry *dentry, - struct iattr *attr) -{ - return -EOPNOTSUPP; -} - static inline void fsverity_cleanup_inode(struct inode *inode) { } @@ -301,22 +294,4 @@ static inline int fsverity_file_open(struct inode *inode, struct file *filp) return 0; } -/** - * fsverity_prepare_setattr() - prepare to change a verity inode's attributes - * @dentry: dentry through which the inode is being changed - * @attr: attributes to change - * - * Verity files are immutable, so deny truncates. This isn't covered by the - * open-time check because sys_truncate() takes a path, not a file descriptor. - * - * Return: 0 on success, -errno on failure - */ -static inline int fsverity_prepare_setattr(struct dentry *dentry, - struct iattr *attr) -{ - if (IS_VERITY(d_inode(dentry))) - return __fsverity_prepare_setattr(dentry, attr); - return 0; -} - #endif /* _LINUX_FSVERITY_H */ -- 2.56.0