[PATCH 4.4 23/54] NFS: fix an incorrect limit in filelayout_decode_layout()

Greg Kroah-Hartman
2021-05-31T13:17:47Z

From: Dan Carpenter <dan.carpenter@oracle.com>

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>
---
fs/nfs/filelayout/filelayout.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -716,7 +716,7 @@ filelayout_decode_layout(struct pnfs_lay
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;