| Message ID | 20230412171441.18958-1-zyytlz.wz@163.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Jiri Kosina |
| Headers | show |
| Series | HID: intel-ish-hid: pci-ish: Fix use after free bug in ish_remove due to race condition | expand |
Hi, I missed some detail in the patch. bh_hbm_work_fn will call ishtp_hbm_dispatch and access &dev->fw_clients in it. Best regards, Zheng Zheng Wang <zyytlz.wz@163.com> 于2023年4月13日周四 01:17写道： > > 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> > --- > 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); > -- > 2.25.1 >
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);
srinivas pandruvada <srinivas.pandruvada@linux.intel.com> 于2023年4月25日周二 23:55写道： > > 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. Got it, thanks! Best regards, Zheng > > > --- > > 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); >
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);
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> --- drivers/hid/intel-ish-hid/ishtp/bus.c | 1 + 1 file changed, 1 insertion(+)