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authorPeter Huewe <huewe.external.infineon@googlemail.com>2011-09-15 14:47:42 -0300
committerGreg Kroah-Hartman <gregkh@suse.de>2011-11-07 13:47:00 -0800
commit2f9b9c0646cee4981675be4b5735a3835a85b7b2 (patch)
tree9e39ec4baf19b0f4908996d641319f7c27b36a13 /drivers
parent4e5edd963b99b4dd54338857a116afea3b99cc74 (diff)
TPM: Zero buffer after copying to userspace
commit 3321c07ae5068568cd61ac9f4ba749006a7185c9 upstream. 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 <srajiv@linux.vnet.ibm.com> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/char/tpm/tpm.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 59078c1844d..6fc23329f3d 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1030,6 +1030,7 @@ 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_scheduled_work();
@@ -1040,8 +1041,11 @@ 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);
}