Merge tag 'efi-urgent-2021-06-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull EFI fixes from Ingo Molnar:
 "A handful of EFI fixes:

   - Fix/robustify a diagnostic printk

   - Fix a (normally not triggered) parser bug in the libstub code

   - Allow !EFI_MEMORY_XP && !EFI_MEMORY_RO entries in the memory map

   - Stop RISC-V from crashing on boot if there's no FDT table"

* tag 'efi-urgent-2021-06-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: cper: fix snprintf() use in cper_dimm_err_location()
  efi/libstub: prevent read overflow in find_file_option()
  efi: Allow EFI_MEMORY_XP and EFI_MEMORY_RO both to be cleared
  efi/fdt: fix panic when no valid fdt found

Author: torvalds

drivers/firmware/efi/cper.c

@@ -276,8 +276,7 @@ static int cper_dimm_err_location(struct cper_mem_err_compact *mem, char *msg)
 	if (!msg || !(mem->validation_bits & CPER_MEM_VALID_MODULE_HANDLE))
 		return 0;
 
-	n = 0;
-	len = CPER_REC_LEN - 1;
+	len = CPER_REC_LEN;
 	dmi_memdev_name(mem->mem_dev_handle, &bank, &device);
 	if (bank && device)
 		n = snprintf(msg, len, "DIMM location: %s %s ", bank, device);
@@ -286,7 +285,6 @@ static int cper_dimm_err_location(struct cper_mem_err_compact *mem, char *msg)
 			     "DIMM location: not present. DMI handle: 0x%.4x ",
 			     mem->mem_dev_handle);
 
-	msg[n] = '\0';
 	return n;
 }
 

drivers/firmware/efi/fdtparams.c

@@ -98,6 +98,9 @@ u64 __init efi_get_fdt_params(struct efi_memory_map_data *mm)
 	BUILD_BUG_ON(ARRAY_SIZE(target) != ARRAY_SIZE(name));
 	BUILD_BUG_ON(ARRAY_SIZE(target) != ARRAY_SIZE(dt_params[0].params));
 
+	if (!fdt)
+		return 0;
+
 	for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
 		node = fdt_path_offset(fdt, dt_params[i].path);
 		if (node < 0)

drivers/firmware/efi/libstub/file.c

@@ -103,7 +103,7 @@ static int find_file_option(const efi_char16_t *cmdline, int cmdline_len,
 		return 0;
 
 	/* Skip any leading slashes */
-	while (cmdline[i] == L'/' || cmdline[i] == L'\\')
+	while (i < cmdline_len && (cmdline[i] == L'/' || cmdline[i] == L'\\'))
 		i++;
 
 	while (--result_len > 0 && i < cmdline_len) {

drivers/firmware/efi/memattr.c

@@ -67,11 +67,6 @@ static bool entry_is_valid(const efi_memory_desc_t *in, efi_memory_desc_t *out)
 		return false;
 	}
 
-	if (!(in->attribute & (EFI_MEMORY_RO | EFI_MEMORY_XP))) {
-		pr_warn("Entry attributes invalid: RO and XP bits both cleared\n");
-		return false;
-	}
-
 	if (PAGE_SIZE > EFI_PAGE_SIZE &&
 	    (!PAGE_ALIGNED(in->phys_addr) ||
 	     !PAGE_ALIGNED(in->num_pages << EFI_PAGE_SHIFT))) {