diff options
| author | Dmitry Osipenko <digetx@gmail.com> | 2021-07-17 21:21:27 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-27 16:31:31 +0200 |
| commit | bf88fef0b6f1488abeca594d377991171c00e52a (patch) | |
| tree | 3a892985dce82d3ad8f9417edbf3543f3e1fbe3a | |
| parent | 00de6a572f30ee93cad7e0704ec4232e5e72bda8 (diff) | |
usb: otg-fsm: Fix hrtimer list corruption
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.
Unable to handle kernel NULL pointer dereference at virtual address 00000126)
...
PC is at __run_timers.part.0+0x150/0x228
LR is at __next_timer_interrupt+0x51/0x9c
...
(__run_timers.part.0) from [<c0187a2b>] (run_timer_softirq+0x2f/0x50)
(run_timer_softirq) from [<c01013ad>] (__do_softirq+0xd5/0x2f0)
(__do_softirq) from [<c012589b>] (irq_exit+0xab/0xb8)
(irq_exit) from [<c0170341>] (handle_domain_irq+0x45/0x60)
(handle_domain_irq) from [<c04c4a43>] (gic_handle_irq+0x6b/0x7c)
(gic_handle_irq) from [<c0100b65>] (__irq_svc+0x65/0xac)
Cc: stable@vger.kernel.org
Acked-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210717182134.30262-6-digetx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/common/usb-otg-fsm.c | 6 | ||||
| -rw-r--r-- | include/linux/usb/otg-fsm.h | 1 |
2 files changed, 6 insertions, 1 deletions
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; }; |