commit: 3ab1aff89477dafb1aaeafe8c8669114a02b7226 From: Tim Gardner <[email protected]> Date: Tue, 6 Dec 2011 11:29:20 -0700 Subject: TPM: Zero buffer whole after copying to userspace
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 <[email protected]> Cc: Debora Velarde <[email protected]> Cc: Rajiv Andrade <[email protected]> Cc: Marcel Selhorst <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Tim Gardner <[email protected]> Signed-off-by: Rajiv Andrade <[email protected]> --- drivers/char/tpm/tpm.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index 32362cf..ad7c732 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -1221,12 +1221,13 @@ ssize_t tpm_read(struct file *file, char __user *buf, 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; -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
