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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Olga Kornievskaia <kolga@netapp.com>,
        Anna Schumaker <Anna.Schumaker@Netapp.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 15/71] NFSv4 remove zero number of fs_locations entries error check
Date:   Mon, 14 Feb 2022 10:25:43 +0100
Message-Id: <20220214092452.536848104@linuxfoundation.org>
In-Reply-To: <20220214092452.020713240@linuxfoundation.org>
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From: Olga Kornievskaia <kolga@netapp.com>

[ Upstream commit 90e12a3191040bd3854d3e236c35921e4e92a044 ]

Remove the check for the zero length fs_locations reply in the
xdr decoding, and instead check for that in the migration code.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfs/nfs4state.c | 3 +++
 fs/nfs/nfs4xdr.c   | 2 --
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index ea680f619438b..aa2caba38a014 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -2070,6 +2070,9 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred
 	}
 
 	result = -NFS4ERR_NXIO;
+	if (!locations->nlocations)
+		goto out;
+
 	if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
 		dprintk("<-- %s: No fs_locations data, migration skipped\n",
 			__func__);
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 0fc08d22c9218..2b7741fe42ead 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3683,8 +3683,6 @@ static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, st
 	if (unlikely(!p))
 		goto out_eio;
 	n = be32_to_cpup(p);
-	if (n <= 0)
-		goto out_eio;
 	for (res->nlocations = 0; res->nlocations < n; res->nlocations++) {
 		u32 m;
 		struct nfs4_fs_location *loc;
-- 
2.34.1