Messages in this thread | | | Subject | Re: [PATCH] mailbox: fix a UAF bug in msg_submit() | From | Xianting TIan <> | Date | Tue, 17 Aug 2021 16:01:08 +0800 |
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在 2021/8/17 下午1:58, Xianting TIan 写道: > > 在 2021/8/17 下午12:29, Jassi Brar 写道: >> On Fri, Aug 6, 2021 at 7:15 AM Xianting Tian >> <xianting.tian@linux.alibaba.com> wrote: >>> We met a UAF issue during our mailbox testing. >>> >>> In synchronous mailbox, we use mbox_send_message() to send a message >>> and wait for completion. mbox_send_message() calls msg_submit() to >>> send the message for the first time, if timeout, it will send the >>> message in tx_tick() for the second time. >>> >> Seems like your controller's .send_data() returns error. Can you >> please explain why it does so? Because >> send_data() only _accepts_ data for further transmission... which >> should seldom be a problem. > > Thanks for the comments, > > We developed virtio-mailbox for heterogeneous virtualization system. > > virtio-mailbox is based on the mialbox framework. > > In virtio framework, its send func 'virtqueue_add_outbuf()' may return > error, which caused .send_data() return error. And also contains > other csenarios. > > But I think mailbox framework shouldn't depend on .send_data() always > return OK, as .send_data() is implemented by mailbox hardware > manufacturer, which is not controlled by mailbox framework itself. > > You said 'seldom', but it still possible we can meet such issue. sucn > as flexrm_send_data() of drivers/mailbox/bcm-flexrm-mailbox.c. > > I think mailbox framework should be work normaly no matter > .send_data() returns ok or not ok. Do you think so? thanks
Another solution is to ignore the return value of .send_data() in msg_submit(),
change
err = chan->mbox->ops->send_data(chan, data); if (!err) { chan->active_req = data; chan->msg_count--; }
to
chan->mbox->ops->send_data(chan, data); chan->active_req = data; chan->msg_count--;
But the side effect of the solution is obvious, as if send failed in the first time, it will have no chance to sent it in tx_tick() for the second time. That is to say, no retry.
So I think the solution in this patch is better.
Looking forward to your further comments, thanks
> >> >> thanks.
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