nfsd4: Fix MACH_CRED NULL dereference

Fixes a NULL-dereference on attempts to use MACH_CRED protection over
auth_sys.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 280acef6f0dc..43f42290e5df 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1264,6 +1264,8 @@ static bool svc_rqst_integrity_protected(struct svc_rqst *rqstp)
         struct svc_cred *cr = &rqstp->rq_cred;
         u32 service;
 
+        if (!cr->cr_gss_mech)
+                return false;
         service = gss_pseudoflavor_to_service(cr->cr_gss_mech, cr->cr_flavor);
         return service == RPC_GSS_SVC_INTEGRITY ||
                service == RPC_GSS_SVC_PRIVACY;