lockd: fix decoding of TEST results

BugLink: https://bugs.launchpad.net/bugs/1857158
[ Upstream commit b8db159239b3f51e2b909859935cc25cb3ff3eed ]

We fail to advance the read pointer when reading the stat.oh field that
identifies the lock-holder in a TEST result.

This turns out not to matter if the server is knfsd, which always
returns a zero-length field.  But other servers (Ganesha is an example)
may not do this.  The result is bad values in fcntl F_GETLK results.

Fix this.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/fs/lockd/clnt4xdr.c b/fs/lockd/clnt4xdr.c
index 00d5ef5f99f73dde4b549087087bc0807d360f43..214a2fa1f1e392a991e1a904316fca3ba3927075 100644 (file)
--- a/fs/lockd/clnt4xdr.c
+++ b/fs/lockd/clnt4xdr.c
@@ -128,24 +128,14 @@ static void encode_netobj(struct xdr_stream *xdr,
 static int decode_netobj(struct xdr_stream *xdr,
                         struct xdr_netobj *obj)
 {
-       u32 length;
-       __be32 *p;
+       ssize_t ret;
 
-       p = xdr_inline_decode(xdr, 4);
-       if (unlikely(p == NULL))
-               goto out_overflow;
-       length = be32_to_cpup(p++);
-       if (unlikely(length > XDR_MAX_NETOBJ))
-               goto out_size;
-       obj->len = length;
-       obj->data = (u8 *)p;
+       ret = xdr_stream_decode_opaque_inline(xdr, (void *)&obj->data,
+                                               XDR_MAX_NETOBJ);
+       if (unlikely(ret < 0))
+               return -EIO;
+       obj->len = ret;
        return 0;
-out_size:
-       dprintk("NFS: returned netobj was too long: %u\n", length);
-       return -EIO;
-out_overflow:
-       print_overflow_msg(__func__, xdr);
-       return -EIO;
 }
 
 /*

diff --git a/fs/lockd/clntxdr.c b/fs/lockd/clntxdr.c
index 2c6176387143c5a6f73ba2a9ae52c39bbd7c98c3..747b9c8c940ac4882fb38606b6294df140bd517c 100644 (file)
--- a/fs/lockd/clntxdr.c
+++ b/fs/lockd/clntxdr.c
@@ -125,24 +125,14 @@ static void encode_netobj(struct xdr_stream *xdr,
 static int decode_netobj(struct xdr_stream *xdr,
                         struct xdr_netobj *obj)
 {
-       u32 length;
-       __be32 *p;
+       ssize_t ret;
 
-       p = xdr_inline_decode(xdr, 4);
-       if (unlikely(p == NULL))
-               goto out_overflow;
-       length = be32_to_cpup(p++);
-       if (unlikely(length > XDR_MAX_NETOBJ))
-               goto out_size;
-       obj->len = length;
-       obj->data = (u8 *)p;
+       ret = xdr_stream_decode_opaque_inline(xdr, (void *)&obj->data,
+                       XDR_MAX_NETOBJ);
+       if (unlikely(ret < 0))
+               return -EIO;
+       obj->len = ret;
        return 0;
-out_size:
-       dprintk("NFS: returned netobj was too long: %u\n", length);
-       return -EIO;
-out_overflow:
-       print_overflow_msg(__func__, xdr);
-       return -EIO;
 }
 
 /*