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>
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committed by
Greg Kroah-Hartman
parent
108885cc28
commit
1d43a87614
@@ -1055,6 +1055,7 @@ ssize_t tpm_read(struct file *file, char __user *buf,
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{
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{
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struct tpm_chip *chip = file->private_data;
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struct tpm_chip *chip = file->private_data;
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ssize_t ret_size;
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ssize_t ret_size;
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int rc;
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del_singleshot_timer_sync(&chip->user_read_timer);
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del_singleshot_timer_sync(&chip->user_read_timer);
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flush_work_sync(&chip->work);
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flush_work_sync(&chip->work);
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@@ -1065,8 +1066,11 @@ ssize_t tpm_read(struct file *file, char __user *buf,
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ret_size = size;
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ret_size = size;
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mutex_lock(&chip->buffer_mutex);
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mutex_lock(&chip->buffer_mutex);
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if (copy_to_user(buf, chip->data_buffer, ret_size))
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rc = copy_to_user(buf, chip->data_buffer, ret_size);
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memset(chip->data_buffer, 0, ret_size);
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if (rc)
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ret_size = -EFAULT;
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ret_size = -EFAULT;
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mutex_unlock(&chip->buffer_mutex);
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mutex_unlock(&chip->buffer_mutex);
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}
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}
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