NFS: fix an incorrect limit in filelayout_decode_layout()

commit 769b01ea68b6c49dc3cde6adf7e53927dacbd3a8 upstream.

The "sizeof(struct nfs_fh)" is two bytes too large and could lead to
memory corruption.  It should be NFS_MAXFHSIZE because that's the size
of the ->data[] buffer.

I reversed the size of the arguments to put the variable on the left.

Fixes: 16b374ca439f ("NFSv4.1: pnfs: filelayout: add driver's LAYOUTGET and GETDEVICEINFO infrastructure")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
index 7f5aa0403e16743c2266c6308cacb9fec20711ea..ae5ed3a0749431586147911dbd916f6d6a355cd6 100644 (file)
--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -718,7 +718,7 @@ filelayout_decode_layout(struct pnfs_layout_hdr *flo,
                if (unlikely(!p))
                        goto out_err;
                fl->fh_array[i]->size = be32_to_cpup(p++);
-               if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
+               if (fl->fh_array[i]->size > NFS_MAXFHSIZE) {
                        printk(KERN_ERR "NFS: Too big fh %d received %d\n",
                               i, fl->fh_array[i]->size);
                        goto out_err;