From b89114cd018cffa5deb7def1844ce1891efd4f96 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 24 Sep 2020 17:58:22 +0200 Subject: [PATCH] efi: mokvar-table: fix some issues in new code Fix a couple of issues in the new mokvar-table handling code, as pointed out by Arvind and Boris: - don't bother checking the end of the physical region against the start address of the mokvar table, - ensure that we enter the loop with err = -EINVAL, - replace size_t with unsigned long to appease pedantic type equality checks. Reviewed-by: Arvind Sankar Reviewed-by: Lenny Szubowicz Tested-by: Borislav Petkov Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/mokvar-table.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) diff --git a/drivers/firmware/efi/mokvar-table.c b/drivers/firmware/efi/mokvar-table.c index b1cd49893d4d..72a9e1736fef 100644 --- a/drivers/firmware/efi/mokvar-table.c +++ b/drivers/firmware/efi/mokvar-table.c @@ -98,15 +98,14 @@ static struct kobject *mokvar_kobj; void __init efi_mokvar_table_init(void) { efi_memory_desc_t md; - u64 end_pa; void *va = NULL; - size_t cur_offset = 0; - size_t offset_limit; - size_t map_size = 0; - size_t map_size_needed = 0; - size_t size; + unsigned long cur_offset = 0; + unsigned long offset_limit; + unsigned long map_size = 0; + unsigned long map_size_needed = 0; + unsigned long size; struct efi_mokvar_table_entry *mokvar_entry; - int err = -EINVAL; + int err; if (!efi_enabled(EFI_MEMMAP)) return; @@ -122,18 +121,16 @@ void __init efi_mokvar_table_init(void) pr_warn("EFI MOKvar config table is not within the EFI memory map\n"); return; } - end_pa = efi_mem_desc_end(&md); - if (efi.mokvar_table >= end_pa) { - pr_err("EFI memory descriptor containing MOKvar config table is invalid\n"); - return; - } - offset_limit = end_pa - efi.mokvar_table; + + offset_limit = efi_mem_desc_end(&md) - efi.mokvar_table; + /* * Validate the MOK config table. Since there is no table header * from which we could get the total size of the MOK config table, * we compute the total size as we validate each variably sized * entry, remapping as necessary. */ + err = -EINVAL; while (cur_offset + sizeof(*mokvar_entry) <= offset_limit) { mokvar_entry = va + cur_offset; map_size_needed = cur_offset + sizeof(*mokvar_entry); @@ -150,7 +147,7 @@ void __init efi_mokvar_table_init(void) offset_limit); va = early_memremap(efi.mokvar_table, map_size); if (!va) { - pr_err("Failed to map EFI MOKvar config table pa=0x%lx, size=%zu.\n", + pr_err("Failed to map EFI MOKvar config table pa=0x%lx, size=%lu.\n", efi.mokvar_table, map_size); return; }