[PATCH 3.16.y-ckt 124/170] nfsd4: fix crash on unknown operation number

[Luis Henriques]

3.16.7-ckt1 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: "J. Bruce Fields" <bfields at redhat.com>

commit 51904b08072a8bf2b9ed74d1bd7a5300a614471d upstream.

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.

Signed-off-by: J. Bruce Fields <bfields at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/nfsd/nfs4proc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 2cbe5d09166a..5d3031ecb1df 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1231,7 +1231,8 @@ 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
-- 
2.1.0