From patchwork Wed Feb 21 21:24:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Seth Forshee (DigitalOcean)" X-Patchwork-Id: 13566430 X-Patchwork-Delegate: paul@paul-moore.com Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 7FB6512E1DF; Wed, 21 Feb 2024 21:25:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708550707; cv=none; b=T8C5TPl4zhOxwfGQSJyTtViA5Q9VIk3mdKsUoADRqMHqFQz8fFjTp4Gd9Logi3hRR06zr/ZkPiX1LZnrqpXFUy/fSXwN/HgXxJj5LU3Lb29+uNe9rBcXk9QHkJSh4RV9SJ/5kqxxc/ZVII49/EbqzOzpSHsmLDHail5+xPBnSj0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708550707; c=relaxed/simple; bh=zODK8f1Oy6szXpHeADRTdhogMg3GAwHuizUWMJpE3DE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=QruHK1h+evfwFcpkYp0fAKRp5bLv5ksY5MUhVuu5Q7O591me5f+3UGo6ZuZEmRtJc25C38C9WIid9iOECUiBjhRl4+zLUQd1r9lNKNLZf4xAcNGyTj511GjHB/zAAosQFifCLyf1A/F+KdDvQkoOPQqy8YwGy04u/MSPXWWvHes= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EZqTenVf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EZqTenVf" Received: by smtp.kernel.org (Postfix) with ESMTPS id 3AB51C4AF75; Wed, 21 Feb 2024 21:25:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708550707; bh=zODK8f1Oy6szXpHeADRTdhogMg3GAwHuizUWMJpE3DE=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=EZqTenVf4PLgedTk1rJ753Y6K4Dpv0W+PXOQ+O6XztyKcvNh1FE7lHIrpUjKps0FB BE8fgzu2nqU0fm1hvmeCWrNIJXyeigiIA6CJtIBy0CeExigttHfIPUNoIReHEj91rS n8dSratBFnSdVJt4+CPzym1SwMREEyF9g1MKfOPrU/LrBhfXNWZMyADs12eTMKAnZn JPBthukiLEhLl/cAkGrEOwLc2PLLboFdudLK5fawpg3Lx45Wnw0Ji1YrBH7/j5jjsS Hyay/OR1tYUESoA6X/0MZ4CH4+tgI4RMh75woXvMMb8jM9tQz/5WP5m4qdMQTxyAgZ FWCPpe1pXmGIQ== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A073C54791; Wed, 21 Feb 2024 21:25:07 +0000 (UTC) From: "Seth Forshee (DigitalOcean)" Date: Wed, 21 Feb 2024 15:24:52 -0600 Subject: [PATCH v2 21/25] ovl: use vfs_{get,set}_fscaps() for copy-up Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240221-idmap-fscap-refactor-v2-21-3039364623bd@kernel.org> References: <20240221-idmap-fscap-refactor-v2-0-3039364623bd@kernel.org> In-Reply-To: <20240221-idmap-fscap-refactor-v2-0-3039364623bd@kernel.org> To: Christian Brauner , Seth Forshee , Serge Hallyn , Paul Moore , Eric Paris , James Morris , Alexander Viro , Jan Kara , Stephen Smalley , Ondrej Mosnacek , Casey Schaufler , Mimi Zohar , Roberto Sassu , Dmitry Kasatkin , Eric Snowberg , "Matthew Wilcox (Oracle)" , Jonathan Corbet , Miklos Szeredi , Amir Goldstein Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, audit@vger.kernel.org, selinux@vger.kernel.org, linux-integrity@vger.kernel.org, linux-doc@vger.kernel.org, linux-unionfs@vger.kernel.org X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=4041; i=sforshee@kernel.org; h=from:subject:message-id; bh=zODK8f1Oy6szXpHeADRTdhogMg3GAwHuizUWMJpE3DE=; =?utf-8?q?b=3DowEBbQGS/pANAwAKAVMDma7l9DHJAcsmYgBl1moryy7rWCDyCKYhTErtw9reV?= =?utf-8?q?BQghynbKThrJ7UB_cXmkPrOJATMEAAEKAB0WIQSQnt+rKAvnETy4Hc9TA5mu5fQxy?= =?utf-8?q?QUCZdZqKwAKCRBTA5mu5fQxyVGuB/_98YVYzC3rmVA+s5SJScrnZ4Y5tk6TMC1IC3?= =?utf-8?q?m8QqEF/wR9kN8x37EMkdEPDIonp4yWwKAp6jK5PHooi_f/TDfrw9dyMvPoFu1mtHO?= =?utf-8?q?k7vcZiK+5YhYlIWrGhaRNAhn89fEQAq8U0XJc0QZMBWZX3zC/JjGALUIe_AXfYqoT?= =?utf-8?q?kymSa8cturCezE9r8NumhzW5fw2Xeam38vDff9hJEQnZdTqoORMKGVWyvWlcy0o7g?= =?utf-8?q?1kEuga_GwQcCqZY7BooJEggxTGYotp66PNUyX0oamXw/4QROT9Cldpj8wp9PrlATv?= =?utf-8?q?F94aP27wamFYLAmAwztP?= 1sjZ5ZJP6nJXzabi+skNTzn9983WmN X-Developer-Key: i=sforshee@kernel.org; a=openpgp; fpr=2ABCA7498D83E1D32D51D3B5AB4800A62DB9F73A X-Endpoint-Received: by B4 Relay for sforshee@kernel.org/default with auth_id=103 Using vfs_{get,set}xattr() for fscaps will be blocked in a future commit, so convert ovl to use the new interfaces. Also remove the now unused ovl_getxattr_value(). Reviewed-by: Amir Goldstein Signed-off-by: Seth Forshee (DigitalOcean) --- fs/overlayfs/copy_up.c | 72 ++++++++++++++++++++++++++------------------------ 1 file changed, 37 insertions(+), 35 deletions(-) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index b8e25ca51016..d7c8d76e2394 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -73,6 +73,23 @@ static int ovl_copy_acl(struct ovl_fs *ofs, const struct path *path, return err; } +static int ovl_copy_fscaps(struct ovl_fs *ofs, const struct path *oldpath, + struct dentry *new) +{ + struct vfs_caps capability; + int err; + + err = vfs_get_fscaps(mnt_idmap(oldpath->mnt), oldpath->dentry, + &capability); + if (err) { + if (err == -ENODATA || err == -EOPNOTSUPP) + return 0; + return err; + } + + return vfs_set_fscaps(ovl_upper_mnt_idmap(ofs), new, &capability, 0); +} + int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct dentry *new) { struct dentry *old = oldpath->dentry; @@ -130,6 +147,14 @@ int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct de break; } + if (is_fscaps_xattr(name)) { + error = ovl_copy_fscaps(OVL_FS(sb), oldpath, new); + if (!error) + continue; + /* fs capabilities must be copied */ + break; + } + retry: size = ovl_do_getxattr(oldpath, name, value, value_size); if (size == -ERANGE) @@ -1039,61 +1064,40 @@ static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, return true; } -static ssize_t ovl_getxattr_value(const struct path *path, char *name, char **value) -{ - ssize_t res; - char *buf; - - res = ovl_do_getxattr(path, name, NULL, 0); - if (res == -ENODATA || res == -EOPNOTSUPP) - res = 0; - - if (res > 0) { - buf = kzalloc(res, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - res = ovl_do_getxattr(path, name, buf, res); - if (res < 0) - kfree(buf); - else - *value = buf; - } - return res; -} - /* Copy up data of an inode which was copied up metadata only in the past. */ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) { struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); struct path upperpath; int err; - char *capability = NULL; - ssize_t cap_size; + struct vfs_caps capability; + bool has_capability = false; ovl_path_upper(c->dentry, &upperpath); if (WARN_ON(upperpath.dentry == NULL)) return -EIO; if (c->stat.size) { - err = cap_size = ovl_getxattr_value(&upperpath, XATTR_NAME_CAPS, - &capability); - if (cap_size < 0) + err = vfs_get_fscaps(mnt_idmap(upperpath.mnt), upperpath.dentry, + &capability); + if (!err) + has_capability = 1; + else if (err != -ENODATA && err != EOPNOTSUPP) goto out; } err = ovl_copy_up_data(c, &upperpath); if (err) - goto out_free; + goto out; /* * Writing to upper file will clear security.capability xattr. We * don't want that to happen for normal copy-up operation. */ ovl_start_write(c->dentry); - if (capability) { - err = ovl_do_setxattr(ofs, upperpath.dentry, XATTR_NAME_CAPS, - capability, cap_size, 0); + if (has_capability) { + err = vfs_set_fscaps(mnt_idmap(upperpath.mnt), upperpath.dentry, + &capability, 0); } if (!err) { err = ovl_removexattr(ofs, upperpath.dentry, @@ -1101,13 +1105,11 @@ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) } ovl_end_write(c->dentry); if (err) - goto out_free; + goto out; ovl_clear_flag(OVL_HAS_DIGEST, d_inode(c->dentry)); ovl_clear_flag(OVL_VERIFIED_DIGEST, d_inode(c->dentry)); ovl_set_upperdata(d_inode(c->dentry)); -out_free: - kfree(capability); out: return err; }