| Message ID | 1604031057-32820-13-git-send-email-bbhatt@codeaurora.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Bug fixes and improvements for MHI power operations | expand |
On Thu, Oct 29, 2020 at 09:10:57PM -0700, Bhaumik Bhatt wrote: > While powering down, the device may or may not acknowledge an MHI > RESET issued by host for a graceful shutdown scenario and end up > sending an incoming data packet after tasklets have been killed. > If a rogue device sends this interrupt for a data transfer event > ring update, it can result in a tasklet getting scheduled while a > clean up is ongoing or has completed and cause access to freed > memory leading to a NULL pointer exception. Remove the interrupt > handlers for MHI event rings early on to avoid this scenario. > > Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Thanks, Mani > --- > drivers/bus/mhi/core/pm.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c > index ffbf6f5..a671f58 100644 > --- a/drivers/bus/mhi/core/pm.c > +++ b/drivers/bus/mhi/core/pm.c > @@ -494,6 +494,7 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl) > for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) { > if (mhi_event->offload_ev) > continue; > + free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event); > tasklet_kill(&mhi_event->task); > } > > @@ -1164,7 +1165,7 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful) > /* Wait for shutdown to complete */ > flush_work(&mhi_cntrl->st_worker); > > - mhi_deinit_free_irq(mhi_cntrl); > + free_irq(mhi_cntrl->irq[0], mhi_cntrl); > > if (!mhi_cntrl->pre_init) { > /* Free all allocated resources */ > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c index ffbf6f5..a671f58 100644 --- a/drivers/bus/mhi/core/pm.c +++ b/drivers/bus/mhi/core/pm.c @@ -494,6 +494,7 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl) for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) { if (mhi_event->offload_ev) continue; + free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event); tasklet_kill(&mhi_event->task); } @@ -1164,7 +1165,7 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful) /* Wait for shutdown to complete */ flush_work(&mhi_cntrl->st_worker); - mhi_deinit_free_irq(mhi_cntrl); + free_irq(mhi_cntrl->irq[0], mhi_cntrl); if (!mhi_cntrl->pre_init) { /* Free all allocated resources */
While powering down, the device may or may not acknowledge an MHI RESET issued by host for a graceful shutdown scenario and end up sending an incoming data packet after tasklets have been killed. If a rogue device sends this interrupt for a data transfer event ring update, it can result in a tasklet getting scheduled while a clean up is ongoing or has completed and cause access to freed memory leading to a NULL pointer exception. Remove the interrupt handlers for MHI event rings early on to avoid this scenario. Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org> --- drivers/bus/mhi/core/pm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)