[34-longterm 039/196] char/tpm: Fix unitialized usage of data buffer

[Paul Gortmaker]

From: Peter Huewe <huewe.external.infineon@xxxxxxxxxxxxxx>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    If you see a problem with using this for longterm, please comment.
                   -------------------

commit 1309d7afbed112f0e8e90be9af975550caa0076b upstream.

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

Reported-by: Peter Huewe <huewe.external@xxxxxxxxxxxx>
Signed-off-by: Peter Huewe <huewe.external@xxxxxxxxxxxx>
Signed-off-by: Marcel Selhorst <m.selhorst@xxxxxxxxxx>
[ 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@xxxxxxxxxxxxxxxxxxxx>

Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 drivers/char/tpm/tpm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 6ab5381..7f95fec 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -956,7 +956,7 @@ 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);
-- 
1.7.9.3

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