On 10/07/24 17:32, Gustavo A. R. Silva wrote:
On 10/07/24 16:55, Kees Cook wrote:While efi_memory_attributes_table_t::entry isn't used directly as an array, it is used as a base for pointer arithmetic. The type is wrong as it's not technically an array of efi_memory_desc_t's; they could be larger. Regardless, leave the type unchanged and remove the old style "0" array size. Additionally replace the open-coded entry offset code with the existing efi_early_memdesc_ptr() helper. Signed-off-by: Kees Cook <kees@xxxxxxxxxx> --- Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> Cc: linux-efi@xxxxxxxxxxxxxxx --- drivers/firmware/efi/memattr.c | 2 +- include/linux/efi.h | 6 +++++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/efi/memattr.c b/drivers/firmware/efi/memattr.c index ab85bf8e165a..01142604e8df 100644 --- a/drivers/firmware/efi/memattr.c +++ b/drivers/firmware/efi/memattr.c @@ -164,7 +164,7 @@ int __init efi_memattr_apply_permissions(struct mm_struct *mm, bool valid; char buf[64]; - valid = entry_is_valid((void *)tbl->entry + i * tbl->desc_size, + valid = entry_is_valid(efi_early_memdesc_ptr(tbl->entry, tbl->desc_size, i), &md); size = md.num_pages << EFI_PAGE_SHIFT; if (efi_enabled(EFI_DBG) || !valid) diff --git a/include/linux/efi.h b/include/linux/efi.h index 418e555459da..b06639c4f6a5 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -607,7 +607,11 @@ typedef struct { u32 num_entries; u32 desc_size; u32 flags; - efi_memory_desc_t entry[0]; + /* + * There are @num_entries following, each of size @desc_size bytes, + * including an efi_memory_desc_t header. + */ + efi_memory_desc_t entry[];a candidate for future __counted_by(num_entries * desc_size) ? :p
ah no, this rather be something more like __sized_by(num_entries * desc_size). -- Gustavo
Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Thanks
