From 3321c07ae5068568cd61ac9f4ba749006a7185c9 Mon Sep 17 00:00:00 2001 From: Peter Huewe Date: Thu, 15 Sep 2011 14:47:42 -0300 Subject: [PATCH] TPM: Zero buffer after copying to userspace Since the buffer might contain security related data it might be a good idea to zero the buffer after we have copied it to userspace. This got assigned CVE-2011-1162. Signed-off-by: Rajiv Andrade Cc: Stable Kernel Signed-off-by: James Morris --- drivers/char/tpm/tpm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index 1fe979335835..9ca5c021d0b6 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -1105,6 +1105,7 @@ ssize_t tpm_read(struct file *file, char __user *buf, { struct tpm_chip *chip = file->private_data; ssize_t ret_size; + int rc; del_singleshot_timer_sync(&chip->user_read_timer); flush_work_sync(&chip->work); @@ -1115,8 +1116,11 @@ ssize_t tpm_read(struct file *file, char __user *buf, ret_size = size; mutex_lock(&chip->buffer_mutex); - if (copy_to_user(buf, chip->data_buffer, ret_size)) + rc = copy_to_user(buf, chip->data_buffer, ret_size); + memset(chip->data_buffer, 0, ret_size); + if (rc) ret_size = -EFAULT; + mutex_unlock(&chip->buffer_mutex); } -- 2.34.1