[PATCH v13 34/59] ceph: make ceph_get_name decrypt filenames

Jeff Layton
2022-04-05T23:52:09Z

When we do a lookupino to the MDS, we get a filename in the trace.
ceph_get_name uses that name directly, so we must properly decrypt
it before copying it to the name buffer.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/ceph/export.c | 44 ++++++++++++++++++++++++++++++++------------
1 file changed, 32 insertions(+), 12 deletions(-)

diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index e0fa66ac8b9f..0ebf2bd93055 100644
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -7,6 +7,7 @@

#include "super.h"
#include "mds_client.h"
+#include "crypto.h"

/*
* Basic fh
@@ -534,7 +535,9 @@ static int ceph_get_name(struct dentry *parent, char *name,
{
struct ceph_mds_client *mdsc;
struct ceph_mds_request *req;
+ struct inode *dir = d_inode(parent);
struct inode *inode = d_inode(child);
+ struct ceph_mds_reply_info_parsed *rinfo;
int err;

if (ceph_snap(inode) != CEPH_NOSNAP)
@@ -546,30 +549,47 @@ static int ceph_get_name(struct dentry *parent, char *name,
if (IS_ERR(req))
return PTR_ERR(req);

- inode_lock(d_inode(parent));
-
+ inode_lock(dir);
req->r_inode = inode;
ihold(inode);
req->r_ino2 = ceph_vino(d_inode(parent));
- req->r_parent = d_inode(parent);
- ihold(req->r_parent);
+ req->r_parent = dir;
+ ihold(dir);
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_num_caps = 2;
err = ceph_mdsc_do_request(mdsc, NULL, req);
+ inode_unlock(dir);

- inode_unlock(d_inode(parent));
+ if (err)
+ goto out;

- if (!err) {
- struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
+ rinfo = &req->r_reply_info;
+ if (!IS_ENCRYPTED(dir)) {
memcpy(name, rinfo->dname, rinfo->dname_len);
name[rinfo->dname_len] = 0;
- dout("get_name %p ino %llx.%llx name %s\n",
- child, ceph_vinop(inode), name);
} else {
- dout("get_name %p ino %llx.%llx err %d\n",
- child, ceph_vinop(inode), err);
- }
+ struct fscrypt_str oname = FSTR_INIT(NULL, 0);
+ struct ceph_fname fname = { .dir = dir,
+ .name = rinfo->dname,
+ .ctext = rinfo->altname,
+ .name_len = rinfo->dname_len,
+ .ctext_len = rinfo->altname_len };
+
+ err = ceph_fname_alloc_buffer(dir, &oname);
+ if (err < 0)
+ goto out;

+ err = ceph_fname_to_usr(&fname, NULL, &oname, NULL);
+ if (!err) {
+ memcpy(name, oname.name, oname.len);
+ name[oname.len] = 0;
+ }
+ ceph_fname_free_buffer(dir, &oname);
+ }
+out:
+ dout("get_name %p ino %llx.%llx err %d %s%s\n",
+ child, ceph_vinop(inode), err,
+ err ? "" : "name ", err ? "" : name);
ceph_mdsc_put_request(req);
return err;
}
--
2.35.1