From 451be8bcdc17c12e01a28d95ec5d8578a13b543a Mon Sep 17 00:00:00 2001 From: Michael Tretter Date: Wed, 8 Sep 2021 14:03:10 +0100 Subject: [PATCH] media: allegro: ignore interrupt if mailbox is not initialized [ Upstream commit 1ecda6393db4be44aba27a243e648dc98c9b92e3 ] The mailbox is initialized after the interrupt handler is installed. As the firmware is loaded and started even later, it should not happen that the interrupt occurs without the mailbox being initialized. As the Linux Driver Verification project (linuxtesting.org) keeps reporting this as an error, add a check to ignore interrupts before the mailbox is initialized to fix this potential null pointer dereference. Reported-by: Yuri Savinykh Reported-by: Nadezda Lutovinova Signed-off-by: Michael Tretter Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/platform/allegro-dvt/allegro-core.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/media/platform/allegro-dvt/allegro-core.c b/drivers/media/platform/allegro-dvt/allegro-core.c index 887b492..14a119b 100644 --- a/drivers/media/platform/allegro-dvt/allegro-core.c +++ b/drivers/media/platform/allegro-dvt/allegro-core.c @@ -2185,6 +2185,15 @@ static irqreturn_t allegro_irq_thread(int irq, void *data) { struct allegro_dev *dev = data; + /* + * The firmware is initialized after the mailbox is setup. We further + * check the AL5_ITC_CPU_IRQ_STA register, if the firmware actually + * triggered the interrupt. Although this should not happen, make sure + * that we ignore interrupts, if the mailbox is not initialized. + */ + if (!dev->mbox_status) + return IRQ_NONE; + allegro_mbox_notify(dev->mbox_status); return IRQ_HANDLED; -- 2.7.4