[PATCH 1/1] pnfs-submit: prevent bad CB_LAYOUTRECALL from crashing client

[Fred Isaman <iisaman@netapp.com>]

An incorrect recall type sent by the server should result in
the client returning BADXDR, not crashing the client.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
---
 fs/nfs/callback_proc.c |    3 +++
 fs/nfs/callback_xdr.c  |    5 ++++-
 2 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index b4c68e9..2274b6f 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -139,6 +139,9 @@ _recall_matches_lget(struct pnfs_cb_lrecall_info *cb_info,
 		return (ino == cb_info->pcl_ino) &&
 			should_free_lseg(range, &cb_args->cbl_range);
 	default:
+		/* Should never hit here, as decode_layoutrecall_args()
+		 * will verify cb_info from server.
+		 */
 		BUG();
 	}
 }
diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index a77877c..2e1a33b 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -246,7 +246,7 @@ static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
 	args->cbl_layoutchanged = ntohl(*p++);
 	args->cbl_recall_type = ntohl(*p++);
 
-	if (likely(args->cbl_recall_type == RETURN_FILE)) {
+	if (args->cbl_recall_type == RETURN_FILE) {
 		args->cbl_range.iomode = iomode;
 		status = decode_fh(xdr, &args->cbl_fh);
 		if (unlikely(status != 0))
@@ -270,6 +270,9 @@ static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
 		}
 		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
 		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
+	} else if (args->cbl_recall_type != RETURN_ALL) {
+		status = htonl(NFS4ERR_BADXDR);
+		goto out;
 	}
 	dprintk("%s: ltype 0x%x iomode %d changed %d recall_type %d\n",
 		__func__,
-- 
1.7.2.1