On Mon, Oct 24, 2022 at 02:33:05PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> Refactor all the open-coded sizeof logic for EFI/EFD log item and log
> format structures into common helper functions whose names reflect the
> struct names.
>
> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> ---
> fs/xfs/libxfs/xfs_log_format.h | 48 ++++++++++++++++++++++++++++
> fs/xfs/xfs_extfree_item.c | 69 ++++++++++++----------------------------
> fs/xfs/xfs_extfree_item.h | 16 +++++++++
> fs/xfs/xfs_super.c | 12 ++-----
> 4 files changed, 88 insertions(+), 57 deletions(-)
>
>
> diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h
> index 2f41fa8477c9..f13e0809dc63 100644
> --- a/fs/xfs/libxfs/xfs_log_format.h
> +++ b/fs/xfs/libxfs/xfs_log_format.h
> @@ -616,6 +616,14 @@ typedef struct xfs_efi_log_format {
> xfs_extent_t efi_extents[]; /* array of extents to free */
> } xfs_efi_log_format_t;
>
> +static inline size_t
> +xfs_efi_log_format_sizeof(
> + unsigned int nr)
> +{
> + return sizeof(struct xfs_efi_log_format) +
> + nr * sizeof(struct xfs_extent);
> +}
These are all just open-coded versions of struct_size(). It's better
to use those, instead, as they will never overflow. (They saturate at
SIZE_MAX.) i.e. what you proposed here:
https://lore.kernel.org/linux-xfs/20210311031745.GT3419940@magnolia/
Otherwise, yeah, looks good.
-Kees
--
Kees Cook
