From: Peter Huewe <huewe.external.infineon@googlemail.com>
Date: Tue, 29 Mar 2011 11:31:25 +0000 (+0200)
Subject: char/tpm: Fix unitialized usage of data buffer
X-Git-Tag: firefly_0821_release~7613^2~1735
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1309d7afbed112f0e8e90be9af975550caa0076b;p=firefly-linux-kernel-4.4.55.git

char/tpm: Fix unitialized usage of data buffer

This patch fixes information leakage to the userspace by initializing
the data buffer to zero.

Reported-by: Peter Huewe <huewe.external@infineon.com>
Signed-off-by: Peter Huewe <huewe.external@infineon.com>
Signed-off-by: Marcel Selhorst <m.selhorst@sirrix.com>
[ Also removed the silly "* sizeof(u8)".  If that isn't 1, we have way
  deeper problems than a simple multiplication can fix.   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 1f46f1cd9225..7beb0e25f1e1 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -980,7 +980,7 @@ int tpm_open(struct inode *inode, struct file *file)
 		return -EBUSY;
 	}
 
-	chip->data_buffer = kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
+	chip->data_buffer = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
 	if (chip->data_buffer == NULL) {
 		clear_bit(0, &chip->is_open);
 		put_device(chip->dev);