4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
commit 1aee9158bc978f91701c5992e395efbc6da2de3c upstream.
... checking that after lock_rename() is too late. Incidentally,
NFSv2 had no nfserr_xdev...
Fixes: aa387d6ce153 "nfsd: fix EXDEV checking in rename"
Cc: stable@xxxxxxxxxxxxxxx # v3.9+
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Acked-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Tested-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfsd/vfs.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1691,6 +1691,12 @@ nfsd_rename(struct svc_rqst *rqstp, stru
if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
goto out;
+ err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
+ if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
+ goto out;
+ if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
+ goto out;
+
host_err = fh_want_write(ffhp);
if (host_err) {
err = nfserrno(host_err);
@@ -1724,12 +1730,6 @@ nfsd_rename(struct svc_rqst *rqstp, stru
if (ndentry == trap)
goto out_dput_new;
- host_err = -EXDEV;
- if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
- goto out_dput_new;
- if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
- goto out_dput_new;
-
host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
if (!host_err) {
host_err = commit_metadata(tfhp);
