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| author | Uttkarsh Aggarwal <quic_uaggarwa@quicinc.com> | 2024-01-19 15:18:25 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-27 16:39:03 -0800 |
| commit | 61a348857e869432e6a920ad8ea9132e8d44c316 (patch) | |
| tree | 5402c19b46709edb5af03a8e6cbecec4928cb928 | |
| parent | de4b5b28c87ccae4da268a53c5df135437f5cfde (diff) | |
| download | linux-stable-61a348857e869432e6a920ad8ea9132e8d44c316.tar.gz linux-stable-61a348857e869432e6a920ad8ea9132e8d44c316.tar.bz2 linux-stable-61a348857e869432e6a920ad8ea9132e8d44c316.zip | |
usb: dwc3: gadget: Fix NULL pointer dereference in dwc3_gadget_suspend
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>
| -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 019368f8e9c4..564976b3e2b9 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4709,15 +4709,13 @@ 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; |