Merge tag 'efi-urgent-for-v6.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI fixes from Ard Biesheuvel:
 "A couple of low-priority EFI fixes:

   - prevent the randstruct plugin from re-ordering EFI protocol
     definitions

   - fix a use-after-free in the capsule loader

   - drop unused variable"

* tag 'efi-urgent-for-v6.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: capsule-loader: Fix use-after-free in efi_capsule_write
  efi/x86: libstub: remove unused variable
  efi: libstub: Disable struct randomization

drivers/firmware/efi/capsule-loader.c

@@ -242,29 +242,6 @@ static ssize_t efi_capsule_write(struct file *file, const char __user *buff,
 	return ret;
 }
 
-/**
- * efi_capsule_flush - called by file close or file flush
- * @file: file pointer
- * @id: not used
- *
- *	If a capsule is being partially uploaded then calling this function
- *	will be treated as upload termination and will free those completed
- *	buffer pages and -ECANCELED will be returned.
- **/
-static int efi_capsule_flush(struct file *file, fl_owner_t id)
-{
-	int ret = 0;
-	struct capsule_info *cap_info = file->private_data;
-
-	if (cap_info->index > 0) {
-		pr_err("capsule upload not complete\n");
-		efi_free_all_buff_pages(cap_info);
-		ret = -ECANCELED;
-	}
-
-	return ret;
-}
-
 /**
  * efi_capsule_release - called by file close
  * @inode: not used
@@ -277,6 +254,13 @@ static int efi_capsule_release(struct inode *inode, struct file *file)
 {
 	struct capsule_info *cap_info = file->private_data;
 
+	if (cap_info->index > 0 &&
+	    (cap_info->header.headersize == 0 ||
+	     cap_info->count < cap_info->total_size)) {
+		pr_err("capsule upload not complete\n");
+		efi_free_all_buff_pages(cap_info);
+	}
+
 	kfree(cap_info->pages);
 	kfree(cap_info->phys);
 	kfree(file->private_data);
@@ -324,7 +308,6 @@ static const struct file_operations efi_capsule_fops = {
 	.owner = THIS_MODULE,
 	.open = efi_capsule_open,
 	.write = efi_capsule_write,
-	.flush = efi_capsule_flush,
 	.release = efi_capsule_release,
 	.llseek = no_llseek,
 };

drivers/firmware/efi/libstub/Makefile

@@ -37,6 +37,13 @@ KBUILD_CFLAGS			:= $(cflags-y) -Os -DDISABLE_BRANCH_PROFILING \
 				   $(call cc-option,-fno-addrsig) \
 				   -D__DISABLE_EXPORTS
 
+#
+# struct randomization only makes sense for Linux internal types, which the EFI
+# stub code never touches, so let's turn off struct randomization for the stub
+# altogether
+#
+KBUILD_CFLAGS := $(filter-out $(RANDSTRUCT_CFLAGS), $(KBUILD_CFLAGS))
+
 # remove SCS flags from all objects in this directory
 KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))
 # disable LTO

drivers/firmware/efi/libstub/x86-stub.c

@@ -220,7 +220,6 @@ adjust_memory_range_protection(unsigned long start, unsigned long size)
 	unsigned long end, next;
 	unsigned long rounded_start, rounded_end;
 	unsigned long unprotect_start, unprotect_size;
-	int has_system_memory = 0;
 
 	if (efi_dxe_table == NULL)
 		return;