recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.14/0053-TPM-Zero-buffer-whole-after-copying-to-userspace.patch

   1 From 6afa33c872ff109ed854c7dcec52130732f9e62e Mon Sep 17 00:00:00 2001
   2 From: Tim Gardner <tim.gardner@canonical.com>
   3 Date: Tue, 6 Dec 2011 11:29:20 -0700
   4 Subject: [PATCH 053/147] TPM: Zero buffer whole after copying to userspace
   5
   6 commit 3ab1aff89477dafb1aaeafe8c8669114a02b7226 upstream.
   7
   8 Commit 3321c07ae5068568cd61ac9f4ba749006a7185c9 correctly clears the TPM
   9 buffer if the user specified read length is >= the TPM buffer length. However,
  10 if the user specified read length is < the TPM buffer length, then part of the
  11 TPM buffer is left uncleared.
  12
  13 Reported-by: Seth Forshee <seth.forshee@canonical.com>
  14 Cc: Debora Velarde <debora@linux.vnet.ibm.com>
  15 Cc: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
  16 Cc: Marcel Selhorst <m.selhorst@sirrix.com>
  17 Cc: tpmdd-devel@lists.sourceforge.net
  18 Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
  19 Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
  20 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  21 ---
  22  drivers/char/tpm/tpm.c |    3 ++-
  23  1 file changed, 2 insertions(+), 1 deletion(-)
  24
  25 diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
  26 index 361a1df..b366b34 100644
  27 --- a/drivers/char/tpm/tpm.c
  28 +++ b/drivers/char/tpm/tpm.c
  29 @@ -1115,12 +1115,13 @@ ssize_t tpm_read(struct file *file, char __user *buf,
  30         ret_size = atomic_read(&chip->data_pending);
  31         atomic_set(&chip->data_pending, 0);
  32         if (ret_size > 0) {     /* relay data */
  33 +               ssize_t orig_ret_size = ret_size;
  34                 if (size < ret_size)
  35                         ret_size = size;
  36
  37                 mutex_lock(&chip->buffer_mutex);
  38                 rc = copy_to_user(buf, chip->data_buffer, ret_size);
  39 -               memset(chip->data_buffer, 0, ret_size);
  40 +               memset(chip->data_buffer, 0, orig_ret_size);
  41                 if (rc)
  42                         ret_size = -EFAULT;
  43
  44 --
  45 1.7.9.4
  46