[PATCH] fs: Set file_handle::handle_bytes before referencing file_handle::f_handle

[Kees Cook <keescook@chromium.org>]

With adding __counted_by(handle_bytes) to struct file_handle, we need
to explicitly set it in the one place it wasn't yet happening prior to
accessing the flex array "f_handle".

Fixes: 1b43c4629756 ("fs: Annotate struct file_handle with __counted_by() and use struct_size()")
Signed-off-by: Kees Cook <keescook@chromium.org>
---
Cc: Christian Brauner <brauner@kernel.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jan Kara <jack@suse.cz>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Cc: linux-hardening@vger.kernel.org
---
 fs/fhandle.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/fhandle.c b/fs/fhandle.c
index 53ed54711cd2..08ec2340dd22 100644
--- a/fs/fhandle.c
+++ b/fs/fhandle.c
@@ -40,6 +40,7 @@ static long do_sys_name_to_handle(const struct path *path,
 			 GFP_KERNEL);
 	if (!handle)
 		return -ENOMEM;
+	handle->handle_bytes = f_handle.handle_bytes;
 
 	/* convert handle size to multiple of sizeof(u32) */
 	handle_dwords = f_handle.handle_bytes >> 2;
-- 
2.34.1