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authorJ. Bruce Fields <bfields@redhat.com>2013-04-15 16:03:46 -0400
committerJ. Bruce Fields <bfields@redhat.com>2013-04-26 16:18:15 -0400
commitaa387d6ce15330e09037947147c5a5a2ba42a0e8 (patch)
treeab9ec0cbd2636e3089db7a10ec49756cce702820 /fs
parent030d794bf49855f5e2a9e8dfbfad34211d1eb08b (diff)
downloadlinux-aa387d6ce15330e09037947147c5a5a2ba42a0e8.tar.bz2
nfsd: fix EXDEV checking in rename
We again check for the EXDEV a little later on, so the first check is redundant. This check is also slightly racier, since a badly timed eviction from the export cache could leave us with the two fh_export pointers pointing to two different cache entries which each refer to the same underlying export. It's better to compare vfsmounts as the later check does, but that leaves a minor security hole in the case where the two exports refer to two different directories especially if (for example) they have different root-squashing options. So, compare ex_path.dentry too. Reported-by: Joe Habermann <joe.habermann@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfsd/vfs.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 2b2e2396a869..84ce601d8063 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1758,10 +1758,6 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
tdentry = tfhp->fh_dentry;
tdir = tdentry->d_inode;
- err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
- if (ffhp->fh_export != tfhp->fh_export)
- goto out;
-
err = nfserr_perm;
if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
goto out;
@@ -1802,6 +1798,8 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
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 = nfsd_break_lease(odentry->d_inode);
if (host_err)