efi/capsule: Fix return code on failing kmap/vmap

If kmap or vmap fail, it means we ran out of memory. There are no
user-provided addressed involved that would justify EFAULT.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170602135207.21708-3-ard.biesheuvel@linaro.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

drivers/firmware/efi/capsule-loader.c

@@ -113,7 +113,7 @@ static ssize_t efi_capsule_submit_update(struct capsule_info *cap_info)
 			VM_MAP, PAGE_KERNEL);
 	if (!cap_hdr_temp) {
 		pr_debug("%s: vmap() failed\n", __func__);
-		return -EFAULT;
+		return -ENOMEM;
 	}
 
 	ret = efi_capsule_update(cap_hdr_temp, cap_info->pages);
@@ -185,7 +185,7 @@ static ssize_t efi_capsule_write(struct file *file, const char __user *buff,
 	kbuff = kmap(page);
 	if (!kbuff) {
 		pr_debug("%s: kmap() failed\n", __func__);
-		ret = -EFAULT;
+		ret = -ENOMEM;
 		goto failed;
 	}
 	kbuff += PAGE_SIZE - cap_info->page_bytes_remain;