Re: [PATCH v3 05/12] usb: otg-fsm: Fix hrtimer list corruption
From: Peter Chen <peter.chen@kernel.org>
Date: 2021-07-06 00:57:50
Also in:
linux-pm, linux-tegra, linux-usb, lkml
On 21-07-05 01:54:26, Dmitry Osipenko wrote:
The HNP work can be re-scheduled while it's still in-fly. This results in re-initialization of the busy work, resetting the hrtimer's list node of the work and crashing kernel with null dereference within kernel/timer once work's timer is expired. It's very easy to trigger this problem by re-plugging USB cable quickly. Initialize HNP work only once to fix this trouble. Cc: stable@vger.kernel.org Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Peter Chen <peter.chen@kernel.org> It is better to append kernel dump if you have v4 patchset. Peter
quoted hunk ↗ jump to hunk
--- drivers/usb/common/usb-otg-fsm.c | 6 +++++- include/linux/usb/otg-fsm.h | 1 + 2 files changed, 6 insertions(+), 1 deletion(-)diff --git a/drivers/usb/common/usb-otg-fsm.c b/drivers/usb/common/usb-otg-fsm.c index 3740cf95560e..0697fde51d00 100644 --- a/drivers/usb/common/usb-otg-fsm.c +++ b/drivers/usb/common/usb-otg-fsm.c@@ -193,7 +193,11 @@ static void otg_start_hnp_polling(struct otg_fsm *fsm) if (!fsm->host_req_flag) return; - INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work); + if (!fsm->hnp_work_inited) { + INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work); + fsm->hnp_work_inited = true; + } + schedule_delayed_work(&fsm->hnp_polling_work, msecs_to_jiffies(T_HOST_REQ_POLL)); }diff --git a/include/linux/usb/otg-fsm.h b/include/linux/usb/otg-fsm.h index 3aee78dda16d..784659d4dc99 100644 --- a/include/linux/usb/otg-fsm.h +++ b/include/linux/usb/otg-fsm.h@@ -196,6 +196,7 @@ struct otg_fsm { struct mutex lock; u8 *host_req_flag; struct delayed_work hnp_polling_work; + bool hnp_work_inited; bool state_changed; };-- 2.32.0
-- Thanks, Peter Chen