ima: based on policy verify firmware signatures (pre-allocated buffer)

Don't differentiate, for now, between kernel_read_file_id READING_FIRMWARE
and READING_FIRMWARE_PREALLOC_BUFFER enumerations.

Fixes: a098ecd firmware: support loading into a pre-allocated buffer (since 4.8)
Signed-off-by: Mimi Zohar <[email protected]>
Cc: Luis R. Rodriguez <[email protected]>
Cc: David Howells <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Serge E. Hallyn <[email protected]>
Cc: Stephen Boyd <[email protected]>

security/integrity/ima/ima_main.c

@@ -447,6 +447,7 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
 
 static int read_idmap[READING_MAX_ID] = {
 	[READING_FIRMWARE] = FIRMWARE_CHECK,
+	[READING_FIRMWARE_PREALLOC_BUFFER] = FIRMWARE_CHECK,
 	[READING_MODULE] = MODULE_CHECK,
 	[READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK,
 	[READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,