[PATCH AUTOSEL for 4.4 22/35] nfsd: check for use of the closed special stateid

Sasha Levin
2018-01-24T04:19:30Z

From: Andrew Elble <aweits@rit.edu>

[ Upstream commit ae254dac721d44c0bfebe2795df87459e2e88219 ]

Prevent the use of the closed (invalid) special stateid by clients.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
fs/nfsd/nfs4state.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 1b05769f18cf..dddf8fd3d058 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -72,6 +72,7 @@ static u64 current_sessionid = 1;
#define ZERO_STATEID(stateid) (!memcmp((stateid), &zero_stateid, sizeof(stateid_t)))
#define ONE_STATEID(stateid) (!memcmp((stateid), &one_stateid, sizeof(stateid_t)))
#define CURRENT_STATEID(stateid) (!memcmp((stateid), &currentstateid, sizeof(stateid_t)))
+#define CLOSE_STATEID(stateid) (!memcmp((stateid), &close_stateid, sizeof(stateid_t)))

/* forward declarations */
static bool check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner);
@@ -4704,7 +4705,8 @@ static __be32 nfsd4_validate_stateid(struct nfs4_client *cl, stateid_t *stateid)
struct nfs4_stid *s;
__be32 status = nfserr_bad_stateid;

- if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
+ if (ZERO_STATEID(stateid) || ONE_STATEID(stateid) ||
+ CLOSE_STATEID(stateid))
return status;
/* Client debugging aid. */
if (!same_clid(&stateid->si_opaque.so_clid, &cl->cl_clientid)) {
@@ -4762,7 +4764,8 @@ nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate,
else if (typemask & NFS4_DELEG_STID)
typemask |= NFS4_REVOKED_DELEG_STID;

- if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
+ if (ZERO_STATEID(stateid) || ONE_STATEID(stateid) ||
+ CLOSE_STATEID(stateid))
return nfserr_bad_stateid;
status = lookup_clientid(&stateid->si_opaque.so_clid, cstate, nn);
if (status == nfserr_stale_clientid) {
--
2.11.0