diff options
| author | Uttkarsh Aggarwal <quic_uaggarwa@quicinc.com> | 2024-01-19 12:48:25 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-02-23 11:24:57 +0300 |
| commit | c7ebd8149ee519d27232e6e4940e9c02071b568b (patch) | |
| tree | 272b4baa20e63a4b61652c669ba16f8493043b5d /drivers/usb/dwc3/gadget.c | |
| parent | ed85777c640cf9e6920bb1b60ed8cd48e1f4d873 (diff) | |
| download | linux-c7ebd8149ee519d27232e6e4940e9c02071b568b.tar.xz | |
usb: dwc3: gadget: Fix NULL pointer dereference in dwc3_gadget_suspend
commit 61a348857e869432e6a920ad8ea9132e8d44c316 upstream.
In current scenario if Plug-out and Plug-In performed continuously
there could be a chance while checking for dwc->gadget_driver in
dwc3_gadget_suspend, a NULL pointer dereference may occur.
Call Stack:
CPU1: CPU2:
gadget_unbind_driver dwc3_suspend_common
dwc3_gadget_stop dwc3_gadget_suspend
dwc3_disconnect_gadget
CPU1 basically clears the variable and CPU2 checks the variable.
Consider CPU1 is running and right before gadget_driver is cleared
and in parallel CPU2 executes dwc3_gadget_suspend where it finds
dwc->gadget_driver which is not NULL and resumes execution and then
CPU1 completes execution. CPU2 executes dwc3_disconnect_gadget where
it checks dwc->gadget_driver is already NULL because of which the
NULL pointer deference occur.
Cc: stable@vger.kernel.org
Fixes: 9772b47a4c29 ("usb: dwc3: gadget: Fix suspend/resume during device mode")
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Uttkarsh Aggarwal <quic_uaggarwa@quicinc.com>
Link: https://lore.kernel.org/r/20240119094825.26530-1-quic_uaggarwa@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/dwc3/gadget.c')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 89de363ecf8b..4c8dd6724678 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4703,15 +4703,13 @@ int dwc3_gadget_suspend(struct dwc3 *dwc) unsigned long flags; int ret; - if (!dwc->gadget_driver) - return 0; - ret = dwc3_gadget_soft_disconnect(dwc); if (ret) goto err; spin_lock_irqsave(&dwc->lock, flags); - dwc3_disconnect_gadget(dwc); + if (dwc->gadget_driver) + dwc3_disconnect_gadget(dwc); spin_unlock_irqrestore(&dwc->lock, flags); return 0; |