On Tue, Oct 19, 2021 at 3:03 AM Gabriel Krisman Bertazi
<krisman@xxxxxxxxxxxxx> wrote:
>
> Non-inode errors will reported with an empty file_handle. In
> preparation for that, allow some events to print the FID record even if
> there isn't any file_handle encoded
>
> Even though FILEID_ROOT is used internally, make zero-length file
> handles be reported as FILEID_INVALID.
>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
> fs/notify/fanotify/fanotify_user.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> index ae848306a017..cd962deefeb7 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -339,9 +339,6 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
> pr_debug("%s: fh_len=%zu name_len=%zu, info_len=%zu, count=%zu\n",
> __func__, fh_len, name_len, info_len, count);
>
> - if (!fh_len)
> - return 0;
> -
> if (WARN_ON_ONCE(len < sizeof(info) || len > count))
> return -EFAULT;
>
> @@ -376,6 +373,11 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
>
> handle.handle_type = fh->type;
> handle.handle_bytes = fh_len;
> +
> + /* Mangle handle_type for bad file_handle */
> + if (!fh_len)
> + handle.handle_type = FILEID_INVALID;
> +
> if (copy_to_user(buf, &handle, sizeof(handle)))
> return -EFAULT;
>
> --
> 2.33.0
>
