From 8920d5ad6ba74ae8ab020e90cc4d976980e68701 Mon Sep 17 00:00:00 2001
From: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Date: Thu, 5 Feb 2009 13:06:30 -0200
Subject: TPM: integrity fix

Fix to function which is called by IMA, now tpm_chip_find_get() considers the case in which the machine doesn't have a TPM or, if it has, its TPM isn't enabled.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 62a5682..ccdd828 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -666,18 +666,20 @@ EXPORT_SYMBOL_GPL(tpm_show_temp_deactivated);
  */
 static struct tpm_chip *tpm_chip_find_get(int chip_num)
 {
-	struct tpm_chip *pos;
+	struct tpm_chip *pos, *chip = NULL;
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 		if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 			continue;
 
-		if (try_module_get(pos->dev->driver->owner))
+		if (try_module_get(pos->dev->driver->owner)) {
+			chip = pos;
 			break;
+		}
 	}
 	rcu_read_unlock();
-	return pos;
+	return chip;
 }
 
 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
-- 
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