Messages in this thread | | | Subject | Re: [PATCH] HID: intel-ish-hid: pci-ish: Fix use after free bug in ish_remove due to race condition | From | srinivas pandruvada <> | Date | Tue, 25 Apr 2023 08:55:12 -0700 |
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On Thu, 2023-04-13 at 01:14 +0800, Zheng Wang wrote: > In ish_probe, it calls ish_dev_init to init the device. In this > function, > ishtp_device_init is called and &dev->bh_hbm_work is bound with > bh_hbm_work_fn. recv_hbm may be called to start the timer work. > > If we remove the module which will call ish_remove to make cleanup, > there may be an unfinished work. The possible sequence is as follows: > > Fix it by canceling the work before cleanup in > ishtp_bus_remove_all_clients > > CPU0 CPUc1 > > |bh_hbm_work_fn > ish_remove | > ishtp_bus_remove_all_clients | > kfree(ishtp_dev->fw_clients); | > | > |&dev->fw_clients[...] > | //use > > Fixes: 3703f53b99e4 ("HID: intel_ish-hid: ISH Transport layer") > Signed-off-by: Zheng Wang <zyytlz.wz@163.com> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
It is a extremely rare case, so it is OK to not mark for stable.
> --- > drivers/hid/intel-ish-hid/ishtp/bus.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/hid/intel-ish-hid/ishtp/bus.c > b/drivers/hid/intel-ish-hid/ishtp/bus.c > index 81385ab37fa9..ada7cd08dbeb 100644 > --- a/drivers/hid/intel-ish-hid/ishtp/bus.c > +++ b/drivers/hid/intel-ish-hid/ishtp/bus.c > @@ -744,6 +744,7 @@ void ishtp_bus_remove_all_clients(struct > ishtp_device *ishtp_dev, > */ > } > spin_unlock_irqrestore(&ishtp_dev->cl_list_lock, flags); > + cancel_work_sync(&ishtp_dev->bh_hbm_work); > > /* Release DMA buffers for client messages */ > ishtp_cl_free_dma_buf(ishtp_dev);
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