[PATCH v13 47/51] nfs: Fix GETATTR bitmap verification

[Andreas Gruenbacher <agruenba@xxxxxxxxxx>]

When decoding GETATTR replies, the client checks the attribute bitmap
for which attributes the server has sent.  It misses bits at the word
boundaries, though; fix that.

Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
 fs/nfs/nfs4xdr.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 788adf3..6f6d921 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -4375,6 +4375,11 @@ static int decode_statfs(struct xdr_stream *xdr, struct 
nfs_fsstat *fsstat)
                goto xdr_error;
        if ((status = decode_attr_files_total(xdr, bitmap, &fsstat->tfiles)) != 
0)
                goto xdr_error;
+
+       status = -EIO;
+       if (unlikely(bitmap[0]))
+               goto xdr_error;
+
        if ((status = decode_attr_space_avail(xdr, bitmap, &fsstat->abytes)) != 
0)
                goto xdr_error;
        if ((status = decode_attr_space_free(xdr, bitmap, &fsstat->fbytes)) != 
0)
@@ -4574,6 +4579,10 @@ static int decode_getfattr_attrs(struct xdr_stream *xdr, 
uint32_t *bitmap,
                goto xdr_error;
        fattr->valid |= status;
 
+       status = -EIO;
+       if (unlikely(bitmap[0]))
+               goto xdr_error;
+
        status = decode_attr_mode(xdr, bitmap, &fmode);
        if (status < 0)
                goto xdr_error;
@@ -4627,6 +4636,10 @@ static int decode_getfattr_attrs(struct xdr_stream *xdr, 
uint32_t *bitmap,
                goto xdr_error;
        fattr->valid |= status;
 
+       status = -EIO;
+       if (unlikely(bitmap[1]))
+               goto xdr_error;
+
        status = decode_attr_mdsthreshold(xdr, bitmap, fattr->mdsthreshold);
        if (status < 0)
                goto xdr_error;
@@ -4789,12 +4802,22 @@ static int decode_fsinfo(struct xdr_stream *xdr, struct 
nfs_fsinfo *fsinfo)
        if ((status = decode_attr_maxwrite(xdr, bitmap, &fsinfo->wtmax)) != 0)
                goto xdr_error;
        fsinfo->wtpref = fsinfo->wtmax;
+
+       status = -EIO;
+       if (unlikely(bitmap[0]))
+               goto xdr_error;
+
        status = decode_attr_time_delta(xdr, bitmap, &fsinfo->time_delta);
        if (status != 0)
                goto xdr_error;
        status = decode_attr_pnfstype(xdr, bitmap, &fsinfo->layouttype);
        if (status != 0)
                goto xdr_error;
+
+       status = -EIO;
+       if (unlikely(bitmap[1]))
+               goto xdr_error;
+
        status = decode_attr_layout_blksize(xdr, bitmap, &fsinfo->blksize);
        if (status)
                goto xdr_error;
-- 
2.5.0