[PATCH 4.1 84/84] nfsd: do nfs4_check_fh in nfs4_check_file instead of nfs4_check_olstateid

From: Greg Kroah-Hartman
Date: Fri Aug 14 2015 - 13:44:31 EST

4.1-stable review patch. If anyone has any objections, please let me know.


From: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>

commit 8fcd461db7c09337b6d2e22d25eb411123f379e3 upstream.

Currently, preprocess_stateid_op calls nfs4_check_olstateid which
verifies that the open stateid corresponds to the current filehandle in the
call by calling nfs4_check_fh.

If the stateid is a NFS4_DELEG_STID however, then no such check is done.
This could cause incorrect enforcement of permissions, because the
nfsd_permission() call in nfs4_check_file uses current the current
filehandle, but any subsequent IO operation will use the file descriptor
in the stateid.

Move the call to nfs4_check_fh into nfs4_check_file instead so that it
can be done for all stateid types.

Signed-off-by: Jeff Layton <jeff.layton@xxxxxxxxxxxxxxx>
[bfields: moved fh check to avoid NULL deref in special stateid case]
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

fs/nfsd/nfs4state.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4397,9 +4397,9 @@ laundromat_main(struct work_struct *laun
queue_delayed_work(laundry_wq, &nn->laundromat_work, t*HZ);

-static inline __be32 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_ol_stateid *stp)
+static inline __be32 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_stid *stp)
- if (!fh_match(&fhp->fh_handle, &stp->st_stid.sc_file->fi_fhandle))
+ if (!fh_match(&fhp->fh_handle, &stp->sc_file->fi_fhandle))
return nfserr_bad_stateid;
return nfs_ok;
@@ -4599,9 +4599,6 @@ nfs4_check_olstateid(struct svc_fh *fhp,
__be32 status;

- status = nfs4_check_fh(fhp, ols);
- if (status)
- return status;
status = nfsd4_check_openowner_confirmed(ols);
if (status)
return status;
@@ -4652,6 +4649,9 @@ nfs4_preprocess_stateid_op(struct net *n
status = nfserr_bad_stateid;
+ if (status)
+ goto out;
+ status = nfs4_check_fh(fhp, s);

if (!status && filpp) {
*filpp = nfs4_find_file(s, flags);
@@ -4761,7 +4761,7 @@ static __be32 nfs4_seqid_op_checks(struc
status = check_stateid_generation(stateid, &stp->st_stid.sc_stateid, nfsd4_has_session(cstate));
if (status)
return status;
- return nfs4_check_fh(current_fh, stp);
+ return nfs4_check_fh(current_fh, &stp->st_stid);


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/