diff --git a/drivers/firmware/efi/mokvar-table.c b/drivers/firmware/efi/mokvar-table.c index 5ed0602c2f75..d865cb1dbaad 100644 --- a/drivers/firmware/efi/mokvar-table.c +++ b/drivers/firmware/efi/mokvar-table.c @@ -103,7 +103,6 @@ void __init efi_mokvar_table_init(void) void *va = NULL; 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; @@ -134,48 +133,34 @@ void __init efi_mokvar_table_init(void) */ err = -EINVAL; while (cur_offset + sizeof(*mokvar_entry) <= offset_limit) { - mokvar_entry = va + cur_offset; - map_size_needed = cur_offset + sizeof(*mokvar_entry); - if (map_size_needed > map_size) { - if (va) - early_memunmap(va, map_size); - /* - * Map a little more than the fixed size entry - * header, anticipating some data. It's safe to - * do so as long as we stay within current memory - * descriptor. - */ - map_size = min(map_size_needed + 2*EFI_PAGE_SIZE, - 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=%lu.\n", - efi.mokvar_table, map_size); - return; - } - mokvar_entry = va + cur_offset; + if (va) + early_memunmap(va, sizeof(*mokvar_entry)); + va = early_memremap(efi.mokvar_table + cur_offset, sizeof(*mokvar_entry)); + if (!va) { + pr_err("Failed to map EFI MOKvar config table pa=0x%lx, size=%zu.\n", + efi.mokvar_table + cur_offset, sizeof(*mokvar_entry)); + return; } + mokvar_entry = va; /* Check for last sentinel entry */ if (mokvar_entry->name[0] == '\0') { if (mokvar_entry->data_size != 0) break; err = 0; + map_size_needed = cur_offset + sizeof(*mokvar_entry); break; } - /* Sanity check that the name is null terminated */ - size = strnlen(mokvar_entry->name, - sizeof(mokvar_entry->name)); - if (size >= sizeof(mokvar_entry->name)) - break; + /* Enforce that the name is NUL terminated */ + mokvar_entry->name[sizeof(mokvar_entry->name) - 1] = '\0'; /* Advance to the next entry */ - cur_offset = map_size_needed + mokvar_entry->data_size; + cur_offset += sizeof(*mokvar_entry) + mokvar_entry->data_size; } if (va) - early_memunmap(va, map_size); + early_memunmap(va, sizeof(*mokvar_entry)); if (err) { pr_err("EFI MOKvar config table is not valid\n"); return;