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@xxxxxxxxxxxxxx>
---
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 */
--
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