From patchwork Wed Nov 29 21:50:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Seth Forshee (DigitalOcean)" X-Patchwork-Id: 13473555 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 8EF8161FC4; Wed, 29 Nov 2023 21:50:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="u8qp9bnx" Received: by smtp.kernel.org (Postfix) with ESMTPS id 184BAC4166B; Wed, 29 Nov 2023 21:50:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1701294658; bh=sdaoEg9ciUZftk2H34h2y651gj0bEkfe58vTpkMB1yM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=u8qp9bnx716v5Vigy7mjHUsLCuMP8nLpRUBvItevXMcTOsgzUh/C15VxsDAxnHLnl bQ/sevGtoOzwHAK/P6s1Zo18UovQyWcEFbX4W76SZ8q1P0JyTEMu+xmk04h5oRQsLK 06M8qxJdHM4mde8Q6t2YQNgR9nAKjPfaB6DSpXKDonVoDRjJq/sx1Gv+d8WEOkdpWW VXg97Wqp3HWq5G0Xo2/Bm+N6G9GP7uibWBcYYDa/vf4CnGyXnXB78uoWIqTZD3uveb K19pyeiRxf6KprihD3McCPOWmlf2ePuYGIzQfzSjw6Ga7CdcMCWHF9fGJWv2mFzxcG 3wjNU9f6+udRQ== 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 09728C4167B; Wed, 29 Nov 2023 21:50:58 +0000 (UTC) From: "Seth Forshee (DigitalOcean)" Date: Wed, 29 Nov 2023 15:50:30 -0600 Subject: [PATCH 12/16] 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: <20231129-idmap-fscap-refactor-v1-12-da5a26058a5b@kernel.org> References: <20231129-idmap-fscap-refactor-v1-0-da5a26058a5b@kernel.org> In-Reply-To: <20231129-idmap-fscap-refactor-v1-0-da5a26058a5b@kernel.org> To: Christian Brauner , Serge Hallyn , Paul Moore , Eric Paris , James Morris , Alexander Viro , 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, linux-unionfs@vger.kernel.org, "Seth Forshee (DigitalOcean)" X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=4000; i=sforshee@kernel.org; h=from:subject:message-id; bh=sdaoEg9ciUZftk2H34h2y651gj0bEkfe58vTpkMB1yM=; =?utf-8?q?b=3DowEBbQGS/pANAwAKAVMDma7l9DHJAcsmYgBlZ7I7nj2pDM1Swf1xxfWdnQF14?= =?utf-8?q?2gaU0cjaKHbr9wa_IfaLDx2JATMEAAEKAB0WIQSQnt+rKAvnETy4Hc9TA5mu5fQxy?= =?utf-8?q?QUCZWeyOwAKCRBTA5mu5fQxyagzB/_9p+FECwvuMkt4XpREQZadycge188mmaG0Bd?= =?utf-8?q?TCbVb2BetQ3LKBPtUkg4sx9fWHrGjDqMTmYASWswk8w_ZxaDGEGJ4Hu1GJI6t42C5?= =?utf-8?q?f0v6yLIm3xXZa54SVpbW6saMAY4YcZBAHtg+Lq5zJqjHxSy/WWSI3lNco_7/L9wXs?= =?utf-8?q?aUPMpHWuiy8v7p4EhXAxCjGiNTCHLkM/2FnayolmIwXVgBMiQ7PSU+KwElFmf/JHB?= =?utf-8?q?mc/CXJ_qy3Ibx41A7h81JLGZSY+rnHq7KdXnC0tbY7F1bbXdlD5Sr0pkfDOA7r7Rp?= =?utf-8?q?laqTUtg48HD5m1hJ7hp5?= YxnKnn+lyAuSXl8IlHlrpCCrEeLE8U 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(). Signed-off-by: Seth Forshee (DigitalOcean) Reviewed-by: Amir Goldstein --- 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 4382881b0709..b43af5ce4b21 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 (!strcmp(name, XATTR_NAME_CAPS)) { + 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) @@ -1006,61 +1031,40 @@ 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, @@ -1068,13 +1072,11 @@ 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; }