Merge branch 'fixes-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull TPM fixes from James Morris:
 "From Jarkko: These are critical fixes for v5.1. Contains also couple
  of new selftests for v5.1 features (partial reads in /dev/tpm0)"

* 'fixes-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  selftests/tpm2: Open tpm dev in unbuffered mode
  selftests/tpm2: Extend tests to cover partial reads
  KEYS: trusted: fix -Wvarags warning
  tpm: Fix the type of the return value in calc_tpm2_event_size()
  KEYS: trusted: allow trusted.ko to initialize w/o a TPM
  tpm: fix an invalid condition in tpm_common_poll
  tpm: turn on TPM on suspend for TPM 1.x

drivers/char/tpm/eventlog/tpm2.c

@@ -37,7 +37,7 @@
  *
  * Returns size of the event. If it is an invalid event, returns 0.
  */
-static int calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
+static size_t calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
 				   struct tcg_pcr_event *event_header)
 {
 	struct tcg_efi_specid_event_head *efispecid;

drivers/char/tpm/tpm-dev-common.c

@@ -233,12 +233,19 @@ __poll_t tpm_common_poll(struct file *file, poll_table *wait)
 	__poll_t mask = 0;
 
 	poll_wait(file, &priv->async_wait, wait);
+	mutex_lock(&priv->buffer_mutex);
 
-	if (!priv->response_read || priv->response_length)
+	/*
+	 * The response_length indicates if there is still response
+	 * (or part of it) to be consumed. Partial reads decrease it
+	 * by the number of bytes read, and write resets it the zero.
+	 */
+	if (priv->response_length)
 		mask = EPOLLIN | EPOLLRDNORM;
 	else
 		mask = EPOLLOUT | EPOLLWRNORM;
 
+	mutex_unlock(&priv->buffer_mutex);
 	return mask;
 }
 

drivers/char/tpm/tpm-interface.c

@@ -402,15 +402,13 @@ int tpm_pm_suspend(struct device *dev)
 	if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
 		return 0;
 
-	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
-		mutex_lock(&chip->tpm_mutex);
 	if (!tpm_chip_start(chip)) {
+		if (chip->flags & TPM_CHIP_FLAG_TPM2)
 			tpm2_shutdown(chip, TPM2_SU_STATE);
-			tpm_chip_stop(chip);
-		}
-		mutex_unlock(&chip->tpm_mutex);
-	} else {
+		else
 			rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
+
+		tpm_chip_stop(chip);
 	}
 
 	return rc;

include/keys/trusted.h

@@ -38,7 +38,7 @@ enum {
 
 int TSS_authhmac(unsigned char *digest, const unsigned char *key,
 			unsigned int keylen, unsigned char *h1,
-			unsigned char *h2, unsigned char h3, ...);
+			unsigned char *h2, unsigned int h3, ...);
 int TSS_checkhmac1(unsigned char *buffer,
 			  const uint32_t command,
 			  const unsigned char *ononce,

security/keys/trusted.c

@@ -125,7 +125,7 @@ static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
  */
 int TSS_authhmac(unsigned char *digest, const unsigned char *key,
 			unsigned int keylen, unsigned char *h1,
-			unsigned char *h2, unsigned char h3, ...)
+			unsigned char *h2, unsigned int h3, ...)
 {
 	unsigned char paramdigest[SHA1_DIGEST_SIZE];
 	struct sdesc *sdesc;
@@ -135,13 +135,16 @@ int TSS_authhmac(unsigned char *digest, const unsigned char *key,
 	int ret;
 	va_list argp;
 
+	if (!chip)
+		return -ENODEV;
+
 	sdesc = init_sdesc(hashalg);
 	if (IS_ERR(sdesc)) {
 		pr_info("trusted_key: can't alloc %s\n", hash_alg);
 		return PTR_ERR(sdesc);
 	}
 
-	c = h3;
+	c = !!h3;
 	ret = crypto_shash_init(&sdesc->shash);
 	if (ret < 0)
 		goto out;
@@ -196,6 +199,9 @@ int TSS_checkhmac1(unsigned char *buffer,
 	va_list argp;
 	int ret;
 
+	if (!chip)
+		return -ENODEV;
+
 	bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
 	tag = LOAD16(buffer, 0);
 	ordinal = command;
@@ -363,6 +369,9 @@ int trusted_tpm_send(unsigned char *cmd, size_t buflen)
 {
 	int rc;
 
+	if (!chip)
+		return -ENODEV;
+
 	dump_tpm_buf(cmd);
 	rc = tpm_send(chip, cmd, buflen);
 	dump_tpm_buf(cmd);
@@ -429,6 +438,9 @@ int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
 {
 	int ret;
 
+	if (!chip)
+		return -ENODEV;
+
 	INIT_BUF(tb);
 	store16(tb, TPM_TAG_RQU_COMMAND);
 	store32(tb, TPM_OIAP_SIZE);
@@ -1245,9 +1257,13 @@ static int __init init_trusted(void)
 {
 	int ret;
 
+	/* encrypted_keys.ko depends on successful load of this module even if
+	 * TPM is not used.
+	 */
 	chip = tpm_default_chip();
 	if (!chip)
-		return -ENOENT;
+		return 0;
+
 	ret = init_digests();
 	if (ret < 0)
 		goto err_put;
@@ -1269,10 +1285,12 @@ static int __init init_trusted(void)
 
 static void __exit cleanup_trusted(void)
 {
+	if (chip) {
 		put_device(&chip->dev);
 		kfree(digests);
 		trusted_shash_release();
 		unregister_key_type(&key_type_trusted);
+	}
 }
 
 late_initcall(init_trusted);

tools/testing/selftests/tpm2/tpm2.py

@@ -22,6 +22,7 @@ TPM2_CC_UNSEAL = 0x015E
 TPM2_CC_FLUSH_CONTEXT = 0x0165
 TPM2_CC_START_AUTH_SESSION = 0x0176
 TPM2_CC_GET_CAPABILITY	= 0x017A
+TPM2_CC_GET_RANDOM = 0x017B
 TPM2_CC_PCR_READ = 0x017E
 TPM2_CC_POLICY_PCR = 0x017F
 TPM2_CC_PCR_EXTEND = 0x0182
@@ -357,9 +358,9 @@ class Client:
         self.flags = flags
 
         if (self.flags & Client.FLAG_SPACE) == 0:
-            self.tpm = open('/dev/tpm0', 'r+b')
+            self.tpm = open('/dev/tpm0', 'r+b', buffering=0)
         else:
-            self.tpm = open('/dev/tpmrm0', 'r+b')
+            self.tpm = open('/dev/tpmrm0', 'r+b', buffering=0)
 
     def close(self):
         self.tpm.close()

tools/testing/selftests/tpm2/tpm2_tests.py

@@ -158,6 +158,69 @@ class SmokeTest(unittest.TestCase):
             pass
         self.assertEqual(rejected, True)
 
+    def test_read_partial_resp(self):
+        try:
+            fmt = '>HIIH'
+            cmd = struct.pack(fmt,
+                              tpm2.TPM2_ST_NO_SESSIONS,
+                              struct.calcsize(fmt),
+                              tpm2.TPM2_CC_GET_RANDOM,
+                              0x20)
+            self.client.tpm.write(cmd)
+            hdr = self.client.tpm.read(10)
+            sz = struct.unpack('>I', hdr[2:6])[0]
+            rsp = self.client.tpm.read()
+        except:
+            pass
+        self.assertEqual(sz, 10 + 2 + 32)
+        self.assertEqual(len(rsp), 2 + 32)
+
+    def test_read_partial_overwrite(self):
+        try:
+            fmt = '>HIIH'
+            cmd = struct.pack(fmt,
+                              tpm2.TPM2_ST_NO_SESSIONS,
+                              struct.calcsize(fmt),
+                              tpm2.TPM2_CC_GET_RANDOM,
+                              0x20)
+            self.client.tpm.write(cmd)
+            # Read part of the respone
+            rsp1 = self.client.tpm.read(15)
+
+            # Send a new cmd
+            self.client.tpm.write(cmd)
+
+            # Read the whole respone
+            rsp2 = self.client.tpm.read()
+        except:
+            pass
+        self.assertEqual(len(rsp1), 15)
+        self.assertEqual(len(rsp2), 10 + 2 + 32)
+
+    def test_send_two_cmds(self):
+        rejected = False
+        try:
+            fmt = '>HIIH'
+            cmd = struct.pack(fmt,
+                              tpm2.TPM2_ST_NO_SESSIONS,
+                              struct.calcsize(fmt),
+                              tpm2.TPM2_CC_GET_RANDOM,
+                              0x20)
+            self.client.tpm.write(cmd)
+
+            # expect the second one to raise -EBUSY error
+            self.client.tpm.write(cmd)
+            rsp = self.client.tpm.read()
+
+        except IOError, e:
+            # read the response
+            rsp = self.client.tpm.read()
+            rejected = True
+            pass
+        except:
+            pass
+        self.assertEqual(rejected, True)
+
 class SpaceTest(unittest.TestCase):
     def setUp(self):
         logging.basicConfig(filename='SpaceTest.log', level=logging.DEBUG)