| Date | Fri, 30 Mar 2012 12:49:29 -0700 | From | Greg KH <> | Subject | [ 056/149] TPM: Zero buffer whole after copying to userspace |
| |
3.2-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tim Gardner <tim.gardner@canonical.com>
commit 3ab1aff89477dafb1aaeafe8c8669114a02b7226 upstream.
Commit 3321c07ae5068568cd61ac9f4ba749006a7185c9 correctly clears the TPM buffer if the user specified read length is >= the TPM buffer length. However, if the user specified read length is < the TPM buffer length, then part of the TPM buffer is left uncleared.
Reported-by: Seth Forshee <seth.forshee@canonical.com> Cc: Debora Velarde <debora@linux.vnet.ibm.com> Cc: Rajiv Andrade <srajiv@linux.vnet.ibm.com> Cc: Marcel Selhorst <m.selhorst@sirrix.com> Cc: tpmdd-devel@lists.sourceforge.net Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/char/tpm/tpm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -1115,12 +1115,13 @@ ssize_t tpm_read(struct file *file, char ret_size = atomic_read(&chip->data_pending); atomic_set(&chip->data_pending, 0); if (ret_size > 0) { /* relay data */ + ssize_t orig_ret_size = ret_size; if (size < ret_size) ret_size = size; mutex_lock(&chip->buffer_mutex); rc = copy_to_user(buf, chip->data_buffer, ret_size); - memset(chip->data_buffer, 0, ret_size); + memset(chip->data_buffer, 0, orig_ret_size); if (rc) ret_size = -EFAULT;
|