From: Jeff Layton <jlayton@kernel.org>
To: ceph-devel@vger.kernel.org
Cc: xiubli@redhat.com, idryomov@gmail.com, lhenriques@suse.de,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v12 29/54] ceph: create symlinks with encrypted and base64-encoded targets
Date: Thu, 31 Mar 2022 11:31:05 -0400 [thread overview]
Message-ID: <20220331153130.41287-30-jlayton@kernel.org> (raw)
In-Reply-To: <20220331153130.41287-1-jlayton@kernel.org>
When creating symlinks in encrypted directories, encrypt and
base64-encode the target with the new inode's key before sending to the
MDS.
When filling a symlinked inode, base64-decode it into a buffer that
we'll keep in ci->i_symlink. When get_link is called, decrypt the buffer
into a new one that will hang off i_link.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/ceph/dir.c | 51 ++++++++++++++++++++---
fs/ceph/inode.c | 107 ++++++++++++++++++++++++++++++++++++++++++------
2 files changed, 141 insertions(+), 17 deletions(-)
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 5ce2a6384e55..82a5f37e9d4a 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -942,6 +942,40 @@ static int ceph_create(struct user_namespace *mnt_userns, struct inode *dir,
return ceph_mknod(mnt_userns, dir, dentry, mode, 0);
}
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+static int prep_encrypted_symlink_target(struct ceph_mds_request *req, const char *dest)
+{
+ int err;
+ int len = strlen(dest);
+ struct fscrypt_str osd_link = FSTR_INIT(NULL, 0);
+
+ err = fscrypt_prepare_symlink(req->r_parent, dest, len, PATH_MAX, &osd_link);
+ if (err)
+ goto out;
+
+ err = fscrypt_encrypt_symlink(req->r_new_inode, dest, len, &osd_link);
+ if (err)
+ goto out;
+
+ req->r_path2 = kmalloc(FSCRYPT_BASE64URL_CHARS(osd_link.len) + 1, GFP_KERNEL);
+ if (!req->r_path2) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ len = fscrypt_base64url_encode(osd_link.name, osd_link.len, req->r_path2);
+ req->r_path2[len] = '\0';
+out:
+ fscrypt_fname_free_buffer(&osd_link);
+ return err;
+}
+#else
+static int prep_encrypted_symlink_target(struct ceph_mds_request *req, const char *dest)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
static int ceph_symlink(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, const char *dest)
{
@@ -973,14 +1007,21 @@ static int ceph_symlink(struct user_namespace *mnt_userns, struct inode *dir,
goto out_req;
}
- req->r_path2 = kstrdup(dest, GFP_KERNEL);
- if (!req->r_path2) {
- err = -ENOMEM;
- goto out_req;
- }
req->r_parent = dir;
ihold(dir);
+ if (IS_ENCRYPTED(req->r_new_inode)) {
+ err = prep_encrypted_symlink_target(req, dest);
+ if (err)
+ goto out_req;
+ } else {
+ req->r_path2 = kstrdup(dest, GFP_KERNEL);
+ if (!req->r_path2) {
+ err = -ENOMEM;
+ goto out_req;
+ }
+ }
+
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 98ac1369b353..08a0885a49f8 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -35,6 +35,7 @@
*/
static const struct inode_operations ceph_symlink_iops;
+static const struct inode_operations ceph_encrypted_symlink_iops;
static void ceph_inode_work(struct work_struct *work);
@@ -638,6 +639,7 @@ void ceph_free_inode(struct inode *inode)
#ifdef CONFIG_FS_ENCRYPTION
kfree(ci->fscrypt_auth);
#endif
+ fscrypt_free_inode(inode);
kmem_cache_free(ceph_inode_cachep, ci);
}
@@ -835,6 +837,34 @@ void ceph_fill_file_time(struct inode *inode, int issued,
inode, time_warp_seq, ci->i_time_warp_seq);
}
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+static int decode_encrypted_symlink(const char *encsym, int enclen, u8 **decsym)
+{
+ int declen;
+ u8 *sym;
+
+ sym = kmalloc(enclen + 1, GFP_NOFS);
+ if (!sym)
+ return -ENOMEM;
+
+ declen = fscrypt_base64url_decode(encsym, enclen, sym);
+ if (declen < 0) {
+ pr_err("%s: can't decode symlink (%d). Content: %.*s\n",
+ __func__, declen, enclen, encsym);
+ kfree(sym);
+ return -EIO;
+ }
+ sym[declen + 1] = '\0';
+ *decsym = sym;
+ return declen;
+}
+#else
+static int decode_encrypted_symlink(const char *encsym, int symlen, u8 **decsym)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
/*
* Populate an inode based on info from mds. May be called on new or
* existing inodes.
@@ -1069,26 +1099,39 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
inode->i_fop = &ceph_file_fops;
break;
case S_IFLNK:
- inode->i_op = &ceph_symlink_iops;
if (!ci->i_symlink) {
u32 symlen = iinfo->symlink_len;
char *sym;
spin_unlock(&ci->i_ceph_lock);
- if (symlen != i_size_read(inode)) {
- pr_err("%s %llx.%llx BAD symlink "
- "size %lld\n", __func__,
- ceph_vinop(inode),
- i_size_read(inode));
+ if (IS_ENCRYPTED(inode)) {
+ if (symlen != i_size_read(inode))
+ pr_err("%s %llx.%llx BAD symlink size %lld\n",
+ __func__, ceph_vinop(inode), i_size_read(inode));
+
+ err = decode_encrypted_symlink(iinfo->symlink, symlen, (u8 **)&sym);
+ if (err < 0) {
+ pr_err("%s decoding encrypted symlink failed: %d\n",
+ __func__, err);
+ goto out;
+ }
+ symlen = err;
i_size_write(inode, symlen);
inode->i_blocks = calc_inode_blocks(symlen);
- }
+ } else {
+ if (symlen != i_size_read(inode)) {
+ pr_err("%s %llx.%llx BAD symlink size %lld\n",
+ __func__, ceph_vinop(inode), i_size_read(inode));
+ i_size_write(inode, symlen);
+ inode->i_blocks = calc_inode_blocks(symlen);
+ }
- err = -ENOMEM;
- sym = kstrndup(iinfo->symlink, symlen, GFP_NOFS);
- if (!sym)
- goto out;
+ err = -ENOMEM;
+ sym = kstrndup(iinfo->symlink, symlen, GFP_NOFS);
+ if (!sym)
+ goto out;
+ }
spin_lock(&ci->i_ceph_lock);
if (!ci->i_symlink)
@@ -1096,7 +1139,17 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
else
kfree(sym); /* lost a race */
}
- inode->i_link = ci->i_symlink;
+
+ if (IS_ENCRYPTED(inode)) {
+ /*
+ * Encrypted symlinks need to be decrypted before we can
+ * cache their targets in i_link. Don't touch it here.
+ */
+ inode->i_op = &ceph_encrypted_symlink_iops;
+ } else {
+ inode->i_link = ci->i_symlink;
+ inode->i_op = &ceph_symlink_iops;
+ }
break;
case S_IFDIR:
inode->i_op = &ceph_dir_iops;
@@ -2125,6 +2178,29 @@ static void ceph_inode_work(struct work_struct *work)
iput(inode);
}
+static const char *ceph_encrypted_get_link(struct dentry *dentry, struct inode *inode,
+ struct delayed_call *done)
+{
+ struct ceph_inode_info *ci = ceph_inode(inode);
+
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
+ return fscrypt_get_symlink(inode, ci->i_symlink, i_size_read(inode), done);
+}
+
+static int ceph_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
+ const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int query_flags)
+{
+ int ret;
+
+ ret = ceph_getattr(mnt_userns, path, stat, request_mask, query_flags);
+ if (ret)
+ return ret;
+ return fscrypt_symlink_getattr(path, stat);
+}
+
/*
* symlinks
*/
@@ -2135,6 +2211,13 @@ static const struct inode_operations ceph_symlink_iops = {
.listxattr = ceph_listxattr,
};
+static const struct inode_operations ceph_encrypted_symlink_iops = {
+ .get_link = ceph_encrypted_get_link,
+ .setattr = ceph_setattr,
+ .getattr = ceph_encrypted_symlink_getattr,
+ .listxattr = ceph_listxattr,
+};
+
int __ceph_setattr(struct inode *inode, struct iattr *attr, struct ceph_iattr *cia)
{
struct ceph_inode_info *ci = ceph_inode(inode);
--
2.35.1
next prev parent reply other threads:[~2022-03-31 15:34 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-31 15:30 [PATCH v12 00/54] ceph+fscrypt: fully-working prototype Jeff Layton
2022-03-31 15:30 ` [PATCH v12 01/54] vfs: export new_inode_pseudo Jeff Layton
2022-03-31 19:50 ` Al Viro
2022-03-31 22:23 ` Jeff Layton
2022-03-31 15:30 ` [PATCH v12 02/54] fscrypt: export fscrypt_base64url_encode and fscrypt_base64url_decode Jeff Layton
2022-03-31 15:30 ` [PATCH v12 03/54] fscrypt: export fscrypt_fname_encrypt and fscrypt_fname_encrypted_size Jeff Layton
2022-03-31 15:30 ` [PATCH v12 04/54] fscrypt: add fscrypt_context_for_new_inode Jeff Layton
2022-03-31 15:30 ` [PATCH v12 05/54] ceph: preallocate inode for ops that may create one Jeff Layton
2022-03-31 15:30 ` [PATCH v12 06/54] ceph: crypto context handling for ceph Jeff Layton
2022-03-31 15:30 ` [PATCH v12 07/54] ceph: support legacy v1 encryption policy keysetup Jeff Layton
2022-03-31 20:16 ` Eric Biggers
2022-04-01 10:22 ` Luís Henriques
2022-03-31 15:30 ` [PATCH v12 08/54] ceph: add a has_stable_inodes operation for ceph Jeff Layton
2022-03-31 20:03 ` Eric Biggers
2022-04-01 10:37 ` Jeff Layton
2022-04-01 18:16 ` Eric Biggers
2022-04-01 18:51 ` Jeff Layton
2022-03-31 15:30 ` [PATCH v12 09/54] ceph: ensure that we accept a new context from MDS for new inodes Jeff Layton
2022-03-31 15:30 ` [PATCH v12 10/54] ceph: add support for fscrypt_auth/fscrypt_file to cap messages Jeff Layton
2022-03-31 15:30 ` [PATCH v12 11/54] ceph: add ability to set fscrypt_auth via setattr Jeff Layton
2022-03-31 15:30 ` [PATCH v12 12/54] ceph: implement -o test_dummy_encryption mount option Jeff Layton
2022-03-31 15:30 ` [PATCH v12 13/54] ceph: decode alternate_name in lease info Jeff Layton
2022-03-31 15:30 ` [PATCH v12 14/54] ceph: add fscrypt ioctls Jeff Layton
2022-03-31 15:30 ` [PATCH v12 15/54] ceph: make the ioctl cmd more readable in debug log Jeff Layton
2022-03-31 15:30 ` [PATCH v12 16/54] ceph: make ceph_msdc_build_path use ref-walk Jeff Layton
2022-03-31 15:30 ` [PATCH v12 17/54] ceph: add encrypted fname handling to ceph_mdsc_build_path Jeff Layton
2022-03-31 15:30 ` [PATCH v12 18/54] ceph: send altname in MClientRequest Jeff Layton
2022-03-31 15:30 ` [PATCH v12 19/54] ceph: encode encrypted name in dentry release Jeff Layton
2022-03-31 15:30 ` [PATCH v12 20/54] ceph: properly set DCACHE_NOKEY_NAME flag in lookup Jeff Layton
2022-03-31 15:30 ` [PATCH v12 21/54] ceph: set DCACHE_NOKEY_NAME in atomic open Jeff Layton
2022-03-31 15:30 ` [PATCH v12 22/54] ceph: make d_revalidate call fscrypt revalidator for encrypted dentries Jeff Layton
2022-03-31 15:30 ` [PATCH v12 23/54] ceph: add helpers for converting names for userland presentation Jeff Layton
2022-03-31 15:31 ` [PATCH v12 24/54] ceph: fix base64 encoded name's length check in ceph_fname_to_usr() Jeff Layton
2022-03-31 15:31 ` [PATCH v12 25/54] ceph: add fscrypt support to ceph_fill_trace Jeff Layton
2022-03-31 15:31 ` [PATCH v12 26/54] ceph: pass the request to parse_reply_info_readdir() Jeff Layton
2022-03-31 15:31 ` [PATCH v12 27/54] ceph: add ceph_encode_encrypted_dname() helper Jeff Layton
2022-03-31 15:31 ` [PATCH v12 28/54] ceph: add support to readdir for encrypted filenames Jeff Layton
2022-03-31 15:31 ` Jeff Layton [this message]
2022-03-31 15:31 ` [PATCH v12 30/54] ceph: make ceph_get_name decrypt filenames Jeff Layton
2022-03-31 15:31 ` [PATCH v12 31/54] ceph: add a new ceph.fscrypt.auth vxattr Jeff Layton
2022-03-31 15:31 ` [PATCH v12 32/54] ceph: add some fscrypt guardrails Jeff Layton
2022-03-31 15:31 ` [PATCH v12 33/54] ceph: don't allow changing layout on encrypted files/directories Jeff Layton
2022-03-31 15:31 ` [PATCH v12 34/54] libceph: add CEPH_OSD_OP_ASSERT_VER support Jeff Layton
2022-03-31 15:31 ` [PATCH v12 35/54] ceph: size handling for encrypted inodes in cap updates Jeff Layton
2022-03-31 15:31 ` [PATCH v12 36/54] ceph: fscrypt_file field handling in MClientRequest messages Jeff Layton
2022-03-31 15:31 ` [PATCH v12 37/54] ceph: get file size from fscrypt_file when present in inode traces Jeff Layton
2022-03-31 15:31 ` [PATCH v12 38/54] ceph: handle fscrypt fields in cap messages from MDS Jeff Layton
2022-03-31 15:31 ` [PATCH v12 39/54] ceph: add __ceph_get_caps helper support Jeff Layton
2022-03-31 15:31 ` [PATCH v12 40/54] ceph: add __ceph_sync_read " Jeff Layton
2022-03-31 15:31 ` [PATCH v12 41/54] ceph: add object version support for sync read Jeff Layton
2022-03-31 15:31 ` [PATCH v12 42/54] ceph: add infrastructure for file encryption and decryption Jeff Layton
2022-03-31 15:31 ` [PATCH v12 43/54] ceph: add truncate size handling support for fscrypt Jeff Layton
2022-03-31 15:31 ` [PATCH v12 44/54] libceph: allow ceph_osdc_new_request to accept a multi-op read Jeff Layton
2022-03-31 15:31 ` [PATCH v12 45/54] ceph: disable fallocate for encrypted inodes Jeff Layton
2022-03-31 15:31 ` [PATCH v12 46/54] ceph: disable copy offload on " Jeff Layton
2022-03-31 15:31 ` [PATCH v12 47/54] ceph: don't use special DIO path for " Jeff Layton
2022-03-31 15:31 ` [PATCH v12 48/54] ceph: align data in pages in ceph_sync_write Jeff Layton
2022-03-31 15:31 ` [PATCH v12 49/54] ceph: add read/modify/write to ceph_sync_write Jeff Layton
2022-03-31 15:31 ` [PATCH v12 50/54] ceph: plumb in decryption during sync reads Jeff Layton
2022-03-31 15:31 ` [PATCH v12 51/54] ceph: add fscrypt decryption support to ceph_netfs_issue_op Jeff Layton
2022-03-31 15:31 ` [PATCH v12 52/54] ceph: set i_blkbits to crypto block size for encrypted inodes Jeff Layton
2022-03-31 15:31 ` [PATCH v12 53/54] ceph: add encryption support to writepage Jeff Layton
2022-03-31 15:31 ` [PATCH v12 54/54] ceph: fscrypt support for writepages Jeff Layton
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