Merge tag 'efi-next-for-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "Only a handful of changes this cycle, consisting of cleanup work and a
  low-prio bugfix:

   - Additional cleanup by Tim for the efivarfs variable name length
     confusion

   - Avoid freeing a bogus pointer when virtual remapping is omitted in
     the EFI boot stub"

* tag 'efi-next-for-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: libstub: only free priv.runtime_map when allocated
  efi: Clear up misconceptions about a maximum variable name size
  efivarfs: Remove unused internal struct members
  Documentation: Mark the 'efivars' sysfs interface as removed
  efi: pstore: Request at most 512 bytes for variable names

3 files changed, 12 insertions, 4 deletions

diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index 833cbb995dd3..5b9dc26e6bcb 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -162,7 +162,15 @@ static ssize_t efi_pstore_read(struct pstore_record *record)
 	efi_status_t status;
 
 	for (;;) {
-		varname_size = 1024;
+		/*
+		 * A small set of old UEFI implementations reject sizes
+		 * above a certain threshold, the lowest seen in the wild
+		 * is 512.
+		 *
+		 * TODO: Commonize with the iteration implementation in
+		 *       fs/efivarfs to keep all the quirks in one place.
+		 */
+		varname_size = 512;
 
 		/*
 		 * If this is the first read() call in the pstore enumeration,
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index 70e9789ff9de..6a337f1f8787 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -335,8 +335,8 @@ fail_free_new_fdt:
 
 fail:
 	efi_free(fdt_size, fdt_addr);
-
-	efi_bs_call(free_pool, priv.runtime_map);
+	if (!efi_novamap)
+		efi_bs_call(free_pool, priv.runtime_map);
 
 	return EFI_LOAD_ERROR;
 }
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index f654e6f6af87..4056ba7f3440 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -215,7 +215,7 @@ efi_status_t efivar_set_variable_locked(efi_char16_t *name, efi_guid_t *vendor,
 
 	if (data_size > 0) {
 		status = check_var_size(nonblocking, attr,
-					data_size + ucs2_strsize(name, 1024));
+					data_size + ucs2_strsize(name, EFI_VAR_NAME_LEN));
 		if (status != EFI_SUCCESS)
 			return status;
 	}