6.1-stable review patch. If anyone has any objections, please let me know.
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From: Uttkarsh Aggarwal quic_uaggarwa@quicinc.com
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 --- drivers/usb/dwc3/gadget.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
--- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4583,15 +4583,13 @@ 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;