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authorPeter Huewe <huewe.external.infineon@googlemail.com>2011-09-15 14:47:42 -0300
committerGreg Kroah-Hartman <gregkh@suse.de>2011-10-03 11:40:58 -0700
commit1d43a87614596faf4b9cae2d0c894aa67a7c5121 (patch)
tree95dacb9911e577b4a4284f0951fc646eb8a48ee0 /drivers/char
parent108885cc2856128a266423d45f617e65961048f7 (diff)
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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/char')
-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 9267629..b85ee76 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1055,6 +1055,7 @@ 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);
@@ -1065,8 +1066,11 @@ 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);
}