nfsd4: fix crash on unknown operation number

Unknown operation numbers are caught in nfsd4_decode_compound() which
sets op->opnum to OP_ILLEGAL and op->status to nfserr_op_illegal.  The
error causes the main loop in nfsd4_proc_compound() to skip most
processing.  But nfsd4_proc_compound also peeks ahead at the next
operation in one case and doesn't take similar precautions there.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index f4bd578bed55..0beb023f25ac 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1272,7 +1272,8 @@ static bool need_wrongsec_check(struct svc_rqst *rqstp)
          */
         if (argp->opcnt == resp->opcnt)
                 return false;
-
+        if (next->opnum == OP_ILLEGAL)
+                return false;
         nextd = OPDESC(next);
         /*
          * Rest of 2.6.3.1.1: certain operations will return WRONGSEC