lkml.org 
[lkml]   [2022]   [Jul]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v1 1/1] bus: mhi: host: Fix up null pointer access in mhi_irq_handler
From
On 7/20/2022 4:04 AM, Qiang Yu wrote:
> The irq handler for a shared IRQ ought to be prepared for running
> even now it's being freed. So let's check the pointer used by
> mhi_irq_handler to avoid null pointer access since it is probably
> released before freeing IRQ.
>
> Signed-off-by: Qiang Yu <quic_qianyu@quicinc.com>
> ---
> drivers/bus/mhi/host/main.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
> index f3aef77a..7959457 100644
> --- a/drivers/bus/mhi/host/main.c
> +++ b/drivers/bus/mhi/host/main.c
> @@ -430,12 +430,20 @@ irqreturn_t mhi_irq_handler(int irq_number, void *dev)
> {
> struct mhi_event *mhi_event = dev;
> struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
> - struct mhi_event_ctxt *er_ctxt =
> - &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
> + struct mhi_event_ctxt *er_ctxt;
> struct mhi_ring *ev_ring = &mhi_event->ring;
> - dma_addr_t ptr = le64_to_cpu(er_ctxt->rp);
> + dma_addr_t ptr;
> void *dev_rp;
>
> + if (!mhi_cntrl->mhi_ctxt) {
> + dev_err(&mhi_cntrl->mhi_dev->dev,
> + "mhi_ctxt has been freed\n");

dev_dbg since you identified a scenario where this is expected?

> + return IRQ_HANDLED;
> + }
> +
> + er_ctxt = &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
> + ptr = le64_to_cpu(er_ctxt->rp);
> +
> if (!is_valid_ring_ptr(ev_ring, ptr)) {
> dev_err(&mhi_cntrl->mhi_dev->dev,
> "Event ring rp points outside of the event ring\n");

\
 
 \ /
  Last update: 2022-07-20 16:17    [W:0.032 / U:0.808 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site