On Wed 15 Nov 12:10 PST 2017, Bjorn Andersson wrote:
> diff --git a/drivers/soc/qcom/qmi_encdec.c b/drivers/soc/qcom/qmi_encdec.c
[..]
> +void *qmi_encode_message(int type, unsigned int msg_id, size_t *len,
> + unsigned int txn_id, struct qmi_elem_info *ei,
> + const void *c_struct)
> +{
> + struct qmi_header *hdr;
> + ssize_t msglen = 0;
> + void *msg;
> + int ret;
> +
> + /* Check the possibility of a zero length QMI message */
> + if (!c_struct) {
> + ret = qmi_calc_min_msg_len(ei, 1);
> + if (ret) {
> + pr_err("%s: Calc. len %d != 0, but NULL c_struct\n",
> + __func__, ret);
> + return ERR_PTR(-EINVAL);
> + }
> + }
> +
> + msg = kzalloc(sizeof(*hdr) + *len, GFP_KERNEL);
> + if (!msg)
> + return ERR_PTR(-ENOMEM);
> +
> + msglen = qmi_encode(ei, msg + sizeof(*hdr), c_struct, *len, 1);
> + if (msglen < 0) {
> + kfree(msg);
> + return ERR_PTR(msglen);
> + }
Talked to Chris Lew about this earlier today;
The check above implies that it's valid to call this function with a
valid ei of minimum message length of 0 and c_struct being NULL. But the
call to qmi_encdec() will dereference c_struct in order to know that the
optional elements described in ei are unset.
So the call to qmi_encode() needs to only be done conditionally on
c_struct being non-NULL, logically interpreting c_struct being NULL as
all optional fields are unset.
Will post an update with this fixed.
> +
> + hdr = msg;
> + hdr->type = type;
> + hdr->txn_id = txn_id;
> + hdr->msg_id = msg_id;
> + hdr->msg_len = msglen;
> +
> + *len = sizeof(*hdr) + msglen;
> +
> + return msg;
> +}
> +EXPORT_SYMBOL(qmi_encode_message);
Regards,
Bjorn
